Choosing an LS Engine for Camaro and Firebird LS Swap • LS Engine DIY (2024)

Many choose iron blocks rather than aluminum versions because they are inexpensive and are easily stroked. They are cheaper and can handle bigger power loads and this is why you see iron-block versions juiced to the hilt with nitrous. However, to be fair to the aluminum versions, I’ve seen some twin-turbo versions of the aluminum block handle power well into the four-digit range.

This tech tip is from the full book, SWAP LS ENGINES INTO CAMAROS & FIREBIRDS: 1967-1981.

For a comprehensive guide on this entire subject you can visit this link: LEARN MORE ABOUT THIS BOOK HERE

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The first cathedral-port head version of the LS1 engine ruffled some feathers. General Motors has since added a square-port design on the LS3. This means that the intakes on the LS1 and LS3 are not interchangeable. With the typical cathedral-port LS6 intake (interchangeable with the LS1) making roughly 320 cfm, the stock LS3 version flows 365 cfm right from the factory. That’s more than your average big-block of days gone by.

Selection Process

Cathedral- and square-port LS engines both have impressive architecture and equipment. Over the years the engines have been relatively compact, able to be stuffed in just about any car that has four wheels and even a few things that didn’t have four wheels. The LS was also extremely reliable; the amount of abuse these engines can take is sometimes just plain astonishing. They are easily repaired; General Motors made millions of these engines and just about everyone has a few 305 blocks lying around as lawn ornaments. Most important, however, to the guys who just can’t leave well enough alone, is that you can easily modify them; the aftermarket for the small-block Chevy is magnificently huge.

Okay, so you’re asking yourself, “So what?” How could this engine really replace almost 45 years of the iron, four-bolt-main small-block that you’ve come to know and love so dearly? Let me count the ways! For starters, the profile of the engine is quite low, allowing it to be stuffed into some very tight spaces and a wide variety of cars. Second, the engine is easy to build and upgrade. It touts a six-bolt main block that can take far more abuse than your granddad’s old iron-block engine, and it does it while weighing 40 pounds lighter. The short-block has been proven to be very reliable up to and beyond 500 hp. Finally, the LS provides excellent potential fuel economy in today’s four-dollar-a-gallon world, so it’s a god-send for guys who like to have plenty of juice on tap but also enjoy a leisurely highway cruise. With a 6-speed T56 tranny, it’s not unheard of to get 25 mpg with an LS engine and a light foot.

The cylinder heads were a massive leap forward and provided an immense boost in power and efficiency. The heads incorporated technology and combustion chamber design from NASCAR SB-2 358-ci race engines. The valve size is roughly the same as a high-performance small-block head (2.165 intake/1.59 exhaust for the LS3 head versus a 2.20 intake/1.60 performance smallblock head). The valve angle was changed slightly and the heads were given a much larger flow rate. More air in equals more power! Now companies, such as Mast Motorsports and West Coast Racing Cylinder Heads, can build you a set of heads for any setup or power level you are trying to achieve. Companies have offerings up to and sometimes beyond the naturally-aspirated 650-hp range from an LS combination and well over 800 hp in a boosted application. General Motors has since upgraded its LS lineup with a host of new engine combinations, each one getting better than the last.

There are of course iron-block versions of the LS engine. However, those were lower compression and mostly put into trucks and SUVs, such as the Silverado and Escalade. If you want a big bore engine and want some forced induction, these are a great way to go. A naturally-aspirated engine can make big power, but it tends be a little more difficult than a forced-induction engine with a supercharger or turbocharger. Many iron-block versions of the LS engine are out there and are by far the most plentiful and the most economical. Up until recently, the LS iron-block engines were the most affordable LS engines for building a potent and powerful stroker combination until General Motors came out with the LS3. This power plant features thicker walled cylinders and easily accepts a stroker kit more readily than the previous LS1 and LS2 short-blocks. It also has the largest bore of the entire lineup at 4.00 inches versus 3.78 of the other blocks, except of course the LS7, which has a 4.125-inch bore. This block (PN 12623967) is nearly equivalent to prepping and machining an iron block for the same purpose. If you choose an iron block, you must realize these are 75 pounds heavier than a similar aluminum-block engine.

Installing an LS engine in your F-Body is often more inexpensive and produces more performance than rebuilding the Gen I small-block that came in your car. With an LS engine, you can ditch that timing light and use a laptop computer to extract a few extra ponies by precisely tuning the ignition curve of the EFI system. No more fiddling with finicky carburetors. On an LS engine, the computer is so efficient and so intelligent that you can set an accurate tune for your engine and you don’t have to be concerned with reliability. A suitable ignition program on your engine can add a lot of horsepower to your build. Finding the right tuner can be a challenge, but suffice to say, it’s important to dyno tune any engine to not only get the most power out of it but also to keep it as reliable as possible. A bad tune can ruin an engine very quickly. Swapping any LS engine into your F-Body can be a breeze if you have the right information, but please do not expect this to be cheap. A typical budget build runs about $10,000 or more. A build, such as this, includes the engine, transmission, and bareminimum parts, such as a stock oil pan, stock intake, injectors, and the standard stock parts. Of course, this depends upon on how effectively you use your hard-earned dollars.

GM LS Engine Architecture

You should ask yourself, “What is the goal of my build?” That’s an important factor when selecting a block, whether it’s aluminum or iron. That goal should guide you through the course of the entire build. This also applies to the type of block you want to run if you choose to build your own or have the choice between aluminum and iron blocks. There are advantages and drawbacks to iron and aluminum blocks.\ The most affordable and economical LS engine version is the iron block. While these blocks can support a lot of horsepower, they are often 100 pounds heavier than their aluminum siblings in the LS lineup. The 5.3L truck block is the most common block found at junkyards these days. Typically, these are inexpensive, but they are also roughly 80 pounds heavier than the aluminum 5.3L block. An iron block’s biggest advantage is that the block itself can withstand higher loads and therefore more horsepower than a comparable aluminum block. For example, if you planned to add forced induction to your engine and expect to make more than 1,000 hp or greater, sticking with the iron block is suitable. You might be tempted to go straight for the 6.0L block because of the price. If you find that the price is similar, the extra cubes do help, but don’t make that much of a power difference in the long run. You can add more power with a good set of heads and a well-suited cam than you can with cubic inches alone.

The aluminum block has advantages and disadvantages as well. While the block itself is considerably lighter at approximately 80 pounds, you have to spend a few more dollars to buy one, especially if you want an LS3 version of the block. At the time of this writing a new bare LS3 block is about $1,300, while a used aluminum 5.3L long block costs about $500 to $750 depending on accessories and condition. In my experience testing with aluminum-blocked LS engines I’ve found that the aluminum versions are typically good up to 1,000 hp but not much more. If I want more than that or I’m trying to introduce a lot of boost with forced induction or nitrous, I want to step up to an iron block because it’s stronger than aluminum. My feeling is that if you really do make more than 1,000 hp, the extra weight of the iron block is truly negligible. I’ve found that the 6.0L versions can fetch a hefty price tag; a recent search for them netted me a few finds in the $1,200 to $1,500 range for the short block alone.

It must be said that all of these engines share design and component similarities but can be vastly different. Many LS parts are interchangeable, but many are not. If you have questions about which parts interchange with particular engines, you need to do some research before purchasing parts. A complete GM LS engine parts interchange guide would fill an entire book so I provide the most important interchange aspects.

To date, General Motors has released more than two-dozen iterations of the LS-series engine. A lot of the engines and parts can be found at salvage yards or more easily through the Chevrolet Performance Parts catalog. The biggest difference between Gen III and Gen IV LS engines is the Gen III has a 24x (26 minus 2) crank reluctor wheel while the Gen IV engine has a 58x (60 minus 2) reluctor wheel for greater computer power and more computing power, this means that the computer has more data points to draw from and can make more accurate timing adjustments to the fuel and air mixture. The easiest way to tell the two engines apart is the Gen III engines have the cam sensor at the top rear of the engine and the Gen IV iterations have the cam sensor closer to the timing cover.

All GM LS engines have similar dimensions or in other words, the length, width, and height of all LS engines is the same. In addition, the engine mounts are located in the same position for almost all engines. Therefore, these compact engines are easily swapped into a first- or second generation F-Body. In fact, the GM LS engine is little smaller than the small-block Chevy but it often sits farther back in the chassis and closer to the firewall. As a result, most LS engines are suitable for swap into an F-Body car. Your choice of an LS engine depends upon your budget, performance goals, and intended use. In this chapter, I provide key information on the major LS engines on the market so use the information to make a wise buying decision. I went to Mike Copeland, one of the gurus of the LS swap for expert information when I did the research for this book. He rose to the rank of project manager of the Concept and Vehicle Integration department in the GM Performance Division and now he is managing operations at Lingenfelter Performance. He taught me just about everything there is to know about these engines and how to make them fit. Throughout this book you find his knowledge and ingenuity sprinkled from cover to cover. Mike provided the follow information.

Below are the basics on most of the LS engines that you come across in today’s market. I hope that this data helps you choose the best engine for your project. General Motors has a few crate engines available if you don’t want to go routing through the scrap yard for picked over cars, those are covered at the end of this chapter.

Gen III Engines

As you well know the GM LS took over for the LT engine, so when the LS1-equipped Corvette was launched in 1997, it ushered in the Gen III LS era. As a guideline, Gen III engines were offered in aluminum block for cars and iron block for trucks. The Gen III line ran concurrently with the Gen IV line from 2005 to 2007. These engines are distinguished by the cathedral-port design heads, which produced excellent low-RPM port velocity.

LS1

Installed in the 1997 Corvette, the LS1 engine was first LS engine ever released to the public. This power plant produced 345 hp and 350 ft-lbs of torque, which for the day wasn’t too shabby coming out of the smog choking 1970s and 1980s era that brought about the K-car. The LS1 features an all-aluminum block and aluminum heads. It featured 15-degree cathedral-port heads that flowed very well. It has a modest compression ratio of 10:1, which works well with a supercharger or other types of power adders. Within a few short years, General Motors installed the LS in a wide range of cars and trucks. General Motors made many of these engines so they’re relatively easy to find. There are many variations in block and head castings.

The first block (PN 12550592), made from 1997 through 1999, had a crossover passage that supplied oil to the right side of the engine. In addition, a small hole drilled through the main webs further promoted “bay-to-bay breathing,” which reduced oil vapor from getting trapped between the main caps.

The 1999–2004 blocks changed little, and the two casting numbers for these years are 12559378 and 12560626. The only thing you might notice is the extra reinforcement on the right front corner and a deep oil slot that improved oil flow to the right side of the engine.

In 2001 and 2002, General Motors changed a few things. At that time, General Motors had a shortage of LS1 blocks and this shortage meant that a few LS6 blocks snuck their way into production. The LS6 (PN 1256118) was the official block for the Corvette in 2001, but it was also installed in some 2001–2002 Camaros. Keep in mind that this did not change anything else on the engine; only the block was different and just because you have one doesn’t always mean that it’s an LS6 right off the bat.

These engines produced 295 to 405 hp, depending on the vehicle in which it was installed. Of course, the Corvette received the 405-hp LS6. Firing order is the same at 1-8-7-2-6- 5-4-3.

As previously mentioned, the LS1 has thin cylinder walls. According to General Motors, the LS1 block should only be limited to .004 inch of cylinder boring for the early blocks and a paltry .010 inch for the later versions. As a result, it’s virtually impossible to obtain big cubes from this engine because of the thin cast-iron sleeves. Without a resleeve of an LS1 block, the maximum stroke is 4.125 inches with a 3.905-inch bore, which calculates to about 393 ci. If you’re searching for larger displacement, I highly recommend finding a suitable iron block or another aluminum version that can be overbored to your requirements. If you want big cubic inches, this isn’t the block for you.

Models: You can find these engines in 1997–2004 Corvettes, 1998–2002 Camaro/Firebird, and 2004 GTOs.

LS6

The LS6 engine is essentially an updated LS1 fitted with bigger and better heads. It has a bigger cam and better flowing heads and intake. The LS6 has more compression than the LS1 at 10.5:1. The LS6 also has slightly better 243 casting heads with sodium-filled exhaust valves and hollow intake valves. The 204/218 cam is also better than the LS1 and carries the obvious LS6 intake over the stock LS1 version. Other than those small pieces and a couple of small-block designs, the LS1 and LS6 are virtually the same. The heads and cam flow very well. Installed in the Corvette Z06, these engines produced a respectable 385 hp and 380 ft-lbs of torque. This was a significant increase from the previous LS1. In 2002, the LS6 (casting number 12551358) saw a bump to 405 hp and 400 ft-lbs, which was a 5-percent increase in output. By the mid- 2000s, the LS6 was getting dated, and in 2004, the LS2 replaced it.

This block is similar to the LS1 in the respect that it has a cast-aluminum block and heads. It was built with 10.5:1 compression and has the standard 1-8-7-2-6-5-4-3 firing order.

Models: 2001–2004 Corvette Z06s and 2004–2005 Cadillac CTS-Vs.

LQ4/LQ9

The iron-block LQ4 and the LQ9 (Vortec 6000) share similar architecture with the LS6, but the difference is that it came in the trucks and SUVs of the GM lineup. Essentially these are the iron-block version of the LS6. It has a 4-inch bore that makes it compatible with the much more desirable L92 and LS7 heads. The heads have a larger combustion chamber than the LS6 head. The LQ9 has a 10.1:1 compression ratio while the LQ4 has a lower 9.4:1 in a 364-ci package. The LQ9 cranks out 345 hp and 385 ft-lbs of torque, while the LQ4 produces a much lower 300 hp and 360 ft-lbs of torque.

Clearly, the LQ9 makes a better starting point for any build and can be bored and stroked to make even more power. Of course, the downside of this combo is that the block adds some weight. That fact may be negligible when considering the power potential. The LQ9 gets bragging rights for being the most powerful engine in the Vortec lineup.

Chevrolet Performance sells this engine through its dealers. Bottom line: If you are looking for a truck LS engine, this is the one to buy.

Models: 1999–2004 Silverado, Suburban, Yukon, and Hummer H2 (LQ4). The LQ9 engine is found in 2002–2006 Escalades and 2003–2007 Silverado SSs and Sierras.

LR4

The LR4 is the 4.3-liter 4800 Vortec. It was rated from 255 hp to 285 hp and 280 to 295 ft-lbs, depending on the year and model of the vehicle you find. These have a small bore and stroke, and are not suitable for high-performance applications.

Models: 2007 Sierra, Savana, Silverado, and Express.

L59/LM7

More than five million LM7, LM4, L33, and the LH6 engines were sold in North American alone. These models are by far the most plentiful of the Gen III and Gen IV engines available. The LM7 is an iron-block version. The cast-iron L59 blocks were built from 1999 to 2007 while the aluminum block was made from 2003 to 2007. The LM7 is basically the same as the LM4 but uses an iron-block. The L59 is available in either 4.8- or 5.3-liter iterations, so verify the casting number to properly identify the displacement of the engine. The 4.8-liter cast–iron block casting number is 12551358. The 2003–2004 models feature the drive-by-wire throttle control system, while earlier models are fitted with a mechanical throttle linkage. The LM7 versions are rated roughly between 285 and 295 hp and 330 ft-lbs of torque depending on model and year. The L59 is a flex fuel version of the LM7, just be aware when picking an engine.

Models: 2002–2005 Cadillac Escalade 2WD, 2002–2006 Avalanche, 2003–2007 Chevrolet Express/ Savana, 1999–2007 GM C/K trucks, 1999–2007 GMC Sierra 1500, 1999– 2006 Suburban/Yukon XL, and 1999–2006 Tahoe/Yukon.

LM4

In 2003 the LM4 was the first Vortec 5300 in the GM lineup to use an aluminum block. This version of the Vortec 5300 is 100 pounds lighter than the LM7 version and has what General Motors calls a “pan-axle,” which allows room for front differential to bolt right onto the oil pan for four-wheel-drive applications. If you plan on a four-wheel-drive swap, this engine just might be the ticket. Rated at 285 and 295 hp and 325 and 335 ft-lbs of torque, again based on model and year.

Models: 2004-and-later TrailBlazer (extended wheel base), 2004 Envoy, and 2004 SSR.

L33

This all-aluminum 5.3-liter truck engine is more commonly found in the extended-cab versions of GM’s C and K lines. This engine is a slight bump up from the LM4 in horsepower to 310, but a decrease in torque to 300 ft-lbs. This Gen III engine was replaced by the Gen IV system. The cylinder heads are based on the LS6 design, which produce more power. These are good finds if you are looking for an all aluminum engine for your swap.

Models: 2005–2007 Silverado and Sierra.

GEN IV Engines

In 2005, General Motors launched a new updated version of the LS engine in the form of the Gen IV. While engine architecture and most of the engine features remain the same on Gen IV engines, there are some key differences. These include the relocated knock sensor (to the outside of block), relocated MAP sensor, longer head bolts (check), and a drive-by-wire throttle body. Most important, these engines feature rectangular ports, generally have better flow characteristics than the Gen III, and therefore produce more power than the earlier Gen III engines.

LSA

Considered the Cadillac version of the LS9, this supercharged 6.2-liter V-8 is installed in the CTS-V, which many call a “family sedan.” The LSA is rated at 556 hp and 551 ft-lbs of torque. The LSA is slightly different than the LS9 in the respect that it has a slightly lower capacity supercharger, 9.0:1 compression compared to the LS9s 9.1:1, a single unit heat exchanger and cast pistons, all of which add up to a little brother version of the LS9. If you’ve had the pleasure of driving one, you know that having one in no way makes for buyer’s remorse for not stepping up to the LS9.

Models: 2009-and-later Cadillac CTS-V and 2012-and-later Camaro ZL1.

LS2

The LS2 is the Gen IV version of the LS1 and LS6 engines. While it uses the same LS6 heads and camshaft, it has a larger 4-inch bore. The compression ratio and power has been bumped up a tad to 10.9:1 and 400 hp/400 ft-lbs of torque with the standard 364 ci. This engine had a limited run before General Motors ushered in the LS3 engine so the LS2 has been superseded.

Models: 2005–2007 Corvette, 2005–2006 SSR, 2005–2006 GTO, 2006–2007 CTS-V, and 2006–2009 TrailBlazer SS.

LS4

The LS4 is a 5.3L engine installed in the Pontiac Grand Prix GXP, Impala, and Monte Carlo. This is the first V-8 to make its way, transversely, into a front-wheel-drive vehicle since 1955. General Motors had to shorten the crank 13 mm, 3 mm from the front and 10 mm from the rear, so it is a bit of an oddball. It features a displacement on demand system and makes 303 hp and 323 ft-lbs of torque. These engines share the same main-cap design and deep skirt model as other LS engines in this series.

Models: 2006–2009 Chevrolet Impala SS, 2006–2007 Chevrolet Monte Carlo SS, 2005–2008 Pontiac Grand Prix GXP, and 2008 Buick LaCrosse Super.

LS7

The LS7 has the largest bore (4.125-inch), and therefore the largest displacement in the LS family. The LS7 is 7.0 liters of pure General Motors fury. I imagine that if General Motors unleashed its most feral engineers and gave them free reign to release their aggression on anything they saw fit, they would come up with this engine. The block has been sleeved so it can be stroked for more cubic inches and boasts a forged crankshaft and main caps. The rods are titanium and pistons are hypereutectic for high-performance service. It has titanium intake and sodiumfilled exhaust valves that allow this engine to rev up to and beyond 7,000 rpm. This engine is a perfect plug-’n’- play engine for those who just want to drop in an easy 505 hp and 470 ft-lbs of torque and be done with it. As General Motors designed it, this is indeed the ultimate smallblock engine.

Models: 2006–2013 Chevrolet Corvette Z06.

LS3

An upgraded and punched-out LS2, the LS3 6.2-liter block replaces the 6.0-liter LS2. Serving as the base engine for the 2008 and newer Corvettes, the new block has a 4.06-inch bore and displaces 376 ci. The all-aluminum engine has 10.7:1 compression and 47-pounds per hour injectors pump out 430 hp and 424 ft-lbs of torque. The extra power comes from the CNC heads, new LS7 injectors, larger bore, new piston, and tweaking of the valvetrain. This engine loves to rev and usually tops out right around 6,600 rpm. These engines are going to be fairly tough to find as they are highly sought after. You might as well order one from Chevrolet Performance or from a builder, such as Mast Motorsports.

Models: 2008-and-later Corvette, 2009 G8 GXP, and 2010-and-later Camaro SS.

LS9

The LS9 is the king of all LS engines at this time. Currently, it is the most powerful American production engine ever made. A supercharged 376-ci engine that bellows out 638 hp and 604 ft-lbs of torque makes this one screaming monster of an LS engine. General Motors decided to forgo the larger LS7, 7.0-liter block due to the internal pressures of the supercharger. They instead went for the LS3 block for its thicker cylinder walls being able to handle the greater pressure. If you are reading this carefully, you’ve noticed I mentioned the LS3 block multiple times. The LS3 at the time of this writing is the only block to go with if you want to make big power and want it to be light. Even General Motors thinks so, as proof by this engine build. These engines only came in the 2009 and newer Corvette ZR1s, so finding one is going to be impossible. You’re better off buying one from Chevrolet Performance as a crate engine and getting yourself a factory warranty.

Models: 2009-and-later Corvette ZR1.

Gen IV Vortec Engines

Gen IV Vortec engines are fairly plentiful at the time of the writing, although finding one might be a bit more challenging. They use Variable Valve Timing and Active Fuel Management (also called Displacement on Demand, by General Motors), and therefore are most complex LS engines.

L76

The L76 is an all-aluminum 6.0- liter Gen IV engine. It uses what General Motors calls Active Fuel Management, which is just another name for its Displacement on Demand system. In essence, what AFM does is it allows the engine to deactivate certain cylinders (under light loads) so they do not fire, thus giving better fuel economy while still retaining the power of 361 hp and 386 ft-lbs when it is needed for heavy engine loads. It also shares a structural oil pan with the Pontiac G8. This engine uses an electric throttle control system that allows the ECM to directly control the throttle engine.

Models: 2007–2009 Chevrolet Suburban, 2007–2009 Chevrolet Avalanche, 2007–2009 Chevrolet Silverado, 2007–2009 GMC Sierra, and 2007–2009 GMC Yukon XL.

L92

The 6.2-liter L92, an all-aluminum engine, is also known as the Vortec 6200. It features variable valve timing and produces a solid 403 hp and 417 ft-lbs of torque. Typically variable valve timing has been reserved for overhead-cam engines, but Chevy figured out a way to make it work with a pushrod setup, making this engine a first of a kind.

Models: 2007-and-later Cadillac Escalade, 2009 Chevrolet Tahoe, 2007 to present GMC Yukon Denali/ Denali XL, 2007 to present GMC Sierra Denali, 2008 to present Hummer H2, 2009 to present Chevrolet Silverado 1500 Vortec Max, 2009 to present GMC Sierra 1500 Vortec Max.

LC9

The LC9 has a compression ratio of 9.9:1 and uses regular unleaded fuel as well as E85. Make sure you grab the ECM to go with the LC9 so it knows that you might run E85 from time to time. Just like its brothers, it uses Active Fuel Management and a returnless fuel-injection arrangement. These engines are found in AWD SUVs and are rated at 302 hp and 330 ft-lbs.

Models: 2007–2013 Chevrolet Avalanche, 2007–2013 Chevrolet Silverado 1500, 2007 to present Chevrolet Suburban 1/2 ton, 2007–2013 GMC Sierra 1500, and 2007 to present GMC Yukon XL 1/2 ton.

This tech tip is from the full book, SWAP LS ENGINES INTO CAMAROS & FIREBIRDS: 1967-1981.

For a comprehensive guide on this entire subject you can visit this link: LEARN MORE ABOUT THIS BOOK HERE

SHARE THIS ARTICLE:Please feel free to share this article on Facebook, in Forums, or with any Clubs you participate in. You can copy and paste this link to share: https://lsenginediy.com/camaro-firebird-ls-swap-engine-subframe-guide/

LFA

This all-aluminum engine was fitted into a few specialty vehicles for General Motors. It touted 6.0 liters and made a respected 332 hp and 367 ft-lbs of torque. It has all the bells and whistles of all the Gen IV engines including Variable Valve Timing and Active Fuel Management.

Models: 2008 to present Chevrolet Tahoe Hybrid, 2008 to present GMC Yukon Hybrid, 2009 to present Cadillac Escalade Hybrid, 2009 to present Chevrolet Silverado Hybrid, and 2009 to present GMC Sierra Hybrid.

LH6

The LH6 is an upgrade from the LM4 for the Gen IV engines. The LH6 is employed with Active Fuel Management and is aluminum, whereas the brother version, the LY5 has an iron block. This is a 5.3-liter block and was the first put into production from the Vortec line. Output is decent at 300 hp and 330 ft-lbs of torque.

Models: 2004–2009 Chevrolet TrailBlazer, including EXT (through 2006), 2005–2009GMC EnvoyDenali, 2005–2006 GMC Envoy XL, 2005 GMC Envoy XUV, 2005–2007 Buick Rainier, 2005–2009 Saab 9-7X, 2007 Chevrolet Silverado 1500, and 2007 GMC Sierra 1500.

LH8

The LH8 is yet another 5.3-liter variant; it was designed for the Hummer H3 and other trucks in GM’s lineup. The difference here is the exhaust that includes a quad catalytic converter system that is compact enough to fit the limited space and fit the EPA’s emissions standards.

Models: 2008 to present Hummer H3 Alpha, and 2009 to present Chevrolet Colorado/GMC Canyon.

LMG

Consider this version the 5.3- liter equivalent of the LY5, except this version can accept flex fuels, such as E85. E85 has grown in popularity due to its cheap price and high-octane rating, which is great for racers looking to make big power on cheap fuel. The downside is that flex fuels, such as E85, are less efficient and while they make better power, they also burn a lot more fuel much more quickly. Expect a conservative loss in fuel mileage between 10 and 20 percent, depending on driving habits.

Models: 2007–2013 Chevrolet Avalanche, 2007–2013 Chevrolet Silverado 1500, 2007 to present Chevrolet Suburban 1/2 ton, 2007 to present Chevrolet Tahoe, 2007 to present GMC Sierra 1500, 2007–2013 GMC Yukon, 2007 to present GMC Yukon XL 1/2 ton.

LY2

The LY2 was new in 2007. It featured a 4.8-liter cast-iron block and aluminum heads. This engine uses the E38 ECM for the system controls. Due to the low displacement, this might be worth a pass when digging through the boneyard.

Models: 2007–2013 Chevrolet Silverado 1500, 2007 to present Chevrolet Tahoe, 2007–2013 GMC Sierra 1500, and 2007 to present GMC Yukon.

LY5

The LY5 is the iron-block version of the LH6. It has a 9.9:1 compression ratio and aluminum heads. It was made from 2007 to the current day. Horsepower is measured at 320 and the torque comes in around 340 ft-lbs.

Models: 2007–2013 Chevrolet Avalanche, 2007–2013 Chevrolet Silverado 1500, 2007–2013 Chevrolet Suburban 1/2 ton, 2007 to present Chevrolet Tahoe, 2007 to present GMC Sierra 1500, 2007 to present GMC Yukon, and 2007 to present GMC Yukon XL 1/2 ton.

LY6

The LY6 is a Gen IV-version of the iron-block version LQ4 and LQ6 engines. While this engine is still using the iron block, it has a few surprises that the previous version did not. This engine has a variable valve time engine management system that really bumps up the output to 353 hp and 373 ft-lbs of torque. It might be wise to snag a few of these if you see them in the boneyards, as I suspect these will be hard to find in the near future. The iron block in combination with the low 9.67:1 compression ratio is literally begging to be super or turbo charged.

Models: 3/4-ton 2007 to present Silverados, Sierras, Suburbans, and Yukons.

Chevrolet Performance Engines

Installing a crate engine offers many advantages over a home engine rebuild. You’re starting with a brand-new factory engine with a warranty. The Chevrolet Performance catalog offers just about any power level and wallet level that you could want. Many of its engines come with generous warrantees and fit great in any vehicle. I mention crate engines because they are readily available and can be built to suit any need. Most of all, they provide performance versions of the popular LS series engines, which really caught my attention.

E-Rod Engines

The E-Rod engine lineup from Chevrolet Performance is Chevrolet’s answer to the growing demand for “green” engines and emissions standards. Chevrolet Performance offers several of its famous engines, such as the LSA, LS3, LS7, and the LS5.3L. These engines are emissions compliant in virtually every state, but it wouldn’t hurt to check your local emission laws to make sure this option is available for you. These engines come with a set of catalytic converters that you add to the current exhaust system and still deliver excellent power.

LS327 (PN 19165628)

This 5.3-liter Chevrolet Performance engine features an iron-block, Grafal-coated pistons, and a performance cam that bumps the power up to 325 hp and 347 ft-lbs. This combination is great for budget conscience rodders, but this engine combo is several thousand bucks cheaper than the LS6 or the newest LS3.

LS376 (PN 19244549)

Call this the souped-up LS3; it is based on the LS3 engine with one major difference: the cam (measuring 112 with 219 intake, 228 exhaust, 1.7 rocker, and 525 intake and exhaust), which you can get via Chevrolet Performance (PN 88958733). With that modification alone, the power jumps to a whopping 480 hp and 475 ft-lbs of torque, just from a cam swap! The power comes in earlier than the stock LS3 due to the cam lobe design.

LSX454 (PN 19244611)

All LS engines have the same external dimensions, including the LSX454. General Motors carved out 454 ci, the famous moniker from the Mark IV big-blocks, all within the confines of the LS block. It is a fully forged engine that has the new LSX six-bolt heads that breathe ultra well. General Motors even throws in a set of fancy “LSX454” orange valve covers that look great at a car show with the hood up. This engine is shipped without any accessories, oil pan, or intake as it’s designed to run EFI or a carb. This engine is rated for a carburetor setup at 620 hp and 600 ft-lbs or 580 hp and 600 ft-lbs with EFI. Just think, with this engine you don’t have to change your fender emblems!

Other LS Engine Builders

You’ve read my reasons for choosing the engine I did after much consideration. Below are a few other options that you may want to look into if you choose to have someone else build your engine. The popularity of LS engines is booming and there’s no shortage of companies willing to build you virtually any power level you desire.

TPiS

Myron Cottrell founded TPiS in 1988. Cottrel has been in the engine sports industry since the 1950s. He taught the art of precise machine work and engine building at a vocational school during the 1970s. TPiS is a proponent of complete engine swaps and, therefore, is providing complete engines and individual components for the LS enthusiast.

TPiS doesn’t just build engines; they race them too. They not only offer tight tolerances and longevity in street and race applications, they use their race knowledge and experience to translate into a better product.

A member of the Engine Masters Challenge, Cotrell’s engines have shown strong results at each competition with a very competitive field. I have had personal experience with this shop and can confidently recommend it as a solid choice for an LS build as well as almost any engine project.

ERL Performance

ERL is probably most wellknown for its 500-ci LS short-block, which makes the small-block-sized LS more like an old-school bigblock Rat engine. ERL offers a great performance line of short-blocks, long-blocks, and stroker kits for the do-it-yourself builder. For example, the company offers a long-block that allows for 427 or 454 ci and promises 680 hp and 580 ft-lbs of torque.

ERL also specializes in sleeving LS blocks and claim these sleeved engines can handle upward of 1,500 hp. To get the 500 ci previously mentioned, they obtain a 4.200-inch bore and a 4.500-inch stroke through the use of an aluminum deck plate and iron sleeves. They call this the LS Superdeck II. All I know is that if I were looking for a solid-performance LS engine, I’d start with an ERL short-block.

Lingenfelter Performance Engineering

Started by John Lingenfelter more than 30 years ago, Lingenfelter has been an established leader in engine sports for three decades. It offers a wide variety of services and products for LS engines and other engine sport endeavors. These products include fuel, exhaust, suspension, electrical, and various other LS components.

Lingenfelter doesn’t simply offer Chevrolet Performance crate engines, but rather the company builds high-performance crate engines based on Chevrolet Performance LS engines. These crate engines are outfitted with premium speed parts, such as Lingenfelter hydraulic roller cams, Lingenfelter heads, Comp Cams double valvesprings, and titanium retainers. Equipped with premium parts, these crate engines command premium prices starting at just over $10,000. For comparison, the Lingenfelter LS3 550-hp crate engine retails for $10,236 while the Chevrolet Performance engine sells for $7,570.

Currently, Lingenfelter offers five different versions of the LS engine in 550-, 575-, 605-, and 650-hp iterations for a variety of applications and budgets. In addition, it offers LS2 road race engine. Lingenfelter also has three versions of the LS7 in 630-, 650-, and 750-hp versions. Finally, if the stock 638-hp LS9 isn’t enough, Lingenfelter offers its LS9, the King Kong of LS engines, in a 750-hp version.

Sourcing from a Junkyard or Salvage Yard

If you source an engine from a salvage yard, the health of the engine cannot be precisely determined. You can take the risk and install the engine in your F-Body car, but you don’t know how well or poorly it will perform. Or how long it will last; you know that it could fail. It may be a running engine. You don’t know if the engine has 200,000 miles on it or if it has a substantially worn valvetrain or, on the other end of the spectrum, a fresh engine with 20,000 miles on it.

You need to closely consider the source of the engine. If you can verify its mileage, source vehicle, and overall condition before it was, you can transplant a salvage yard engine into your F-Body car without a rebuild, and you can do it with a large measure of confidence. To be absolutely certain of the condition of the engine, you need to perform a complete rebuild. While that may not be necessary for all salvage yard engines, I recommend a complete rebuild for these engines.

While that’s a lot of work, it’s the only certain way to ensure the engine will be reliable and perform at its best. Besides, it allows you to upgrade pistons, rods, cam, and valvetrain for more torque and horsepower. You could also build the engine to accept a power adder. Once you have an idea of how the engine will be used, it is a lot easier to match the build to your needs. Matching reliability and power is always a major consideration. The bigger the power output, the more you need more stout parts.

If you are having an engine built for you, it’s best to have a detailed conversation with the builder about major components and the major machining phases. You need to specify your performance goals, application, and budget. If you’re rebuilding an engine, you can easily install a stroker package without a lot of additional expense. You need to select a suitable rotating assembly for your block and have the block machined to attain the proper clearances. The final cubic-inch size is just as major a consideration as the head and cam package. All of the parts have to work as a matched system and weak links need to be weeded out.

If you choose to source your engine from a local salvage yard, you need to choose your engine wisely. Most important, you need to provide precise instructions to parts pickers, so you get the entire engine and all the essential accessories to run the engine. You need a couple of key phrases for your proprietor so you can speak the lingo. Typically, parts pickers at junkyards aren’t very careful when they grab parts you ask for. Most often, they won’t be as careful and prefer to remove parts with an oxyacetylene torch rather than a wrench. To ensure you get an entire engine with all the accessories you need, you want to ask for a “pullout.” This means that it includes the front-drive accessories and anything physically bolted onto the engine, such as a starter. Before handing over any money, you should clarify exactly what you want to buy because sometimes things get lost in the transaction.

You need to ask that they carefully and cautiously remove the wiring harness, so that they don’t haphazardly remove it with wire cutters. It’s imperative that you ask them for the ECM and/or TCM unless you’re going to use an aftermarket system. Without the ECM, an engine cannot run and integrating a different ECM to your engine requires reflashing the ECM, so now you know why it’s imperative. It takes more time to remove this and may cost you a couple extra dollars to have it happen, but it can save you a lot of extra money in the long run if you have a little patience with the junkyard.

Now that you have a “new to you” engine, you want to inspect and evaluate it for any major problems. First and foremost, visually inspect the engine itself. Make sure the block doesn’t have any exterior cracks or obvious signs of damage. A crack in the block could mean a thrown rod.

Second, before you purchase it, make sure the crankshaft turns over. If you buy a seized engine, you won’t be sure of the extent of the damage or problems until you disassemble the engine. You may be into an expensive rebuild.

Then check all the sensors to make sure they haven’t been broken off and that the wiring hasn’t been cut or tampered with. Typically, the fuse block does not come with a pullout because the LS fuse block is integrated with the rest of the vehicle; it’s not practical to have this included with your purchase.

A complete visual inspection should include the intake for obvious signs of damage because it is a plastic piece and they have been known to crack.

An inspection of the accessories should be next. Make sure the correct accessories are in place, that they spin freely, and the bearings aren’t worn out. Using a breaker bar to spin the crank also suffices, assuming there’s a belt to run the accessories.

Finally, check the casting number to make sure you got the correct engine.

Engine Disassembly

Once you’re satisfied with the exterior inspection, it’s time to dive into the engine itself. I strongly recommend that you rebuild any used engine because you have no idea how the engine has been maintained or operated. If you want to ensure that you have a strong and reliable engine, it’s best to rebuild the engine before it’s installed in the chassis. It’s better to spend the time, effort, and money now so that you don’t have to do it later with some unknown surprise.

At this stage, disassemble the engine carefully and mark each part as you take it off for further reference. The plastic intake should be thoroughly inspected to make sure it isn’t cracked or broken around the throttle body and the intake ports. From there, carefully disassemble and inspect the heads, making sure to look at each spring and valve that you take out for any bends or broken pieces. You need to have the head or block casting parts Magnafluxed to identify any crack or problem. The process exposes cracks, defects, and other imperfections that you cannot see with the naked eye.

With any junkyard engine, you need to go through the short-block. Remove each of the main caps to check the crank bearings to see if the engine has ever been abused or starved of oil. Leave one main cap on and remove all the piston and connecting rod assemblies. Check again for any abuse or oiling problems. If there’s any deep scarring of the crankshaft or a spun bearing, you can quickly identify the problem. In the case of the crankshaft, you have to determine if you can turn down the journal; if there is not enough material and oversized bearings cannot be used, you may need to replace the crank. If the bearings are damaged, have a machinist press them off and replace them. After you’ve pulled the pistons and checked them for damage, look inside the piston bores and check for scarring or other signs of damage to the cylinder walls.

After you’ve completed the disassembly process, take your heads and block to a local machine shop for cleaning in a hot tank and Magnaflux crack inspection of the heads. If you’re building your own engine, it may be helpful to have the machine shop install the cam bearings for you as they can be tricky to get seated properly. Expect a couple of weeks worth of time for turnaround and a couple of bucks out of your pocket.

I always recommend new bolts for any rebuild because bolts deteriorate over time and the clamping force decreases. Your bolts must be able to hold the correct amount of clamping force or the fasteners will be out of spec. That means the engine could suffer a failure. Many engines, mine included, come with a torque-toyield style of bolts. Therefore, when the bolt has been properly torqued for the first time, it cannot be re-used as it most likely stretched. It’s cheap insurance to buy new bolts. Always use plenty of assembly lube and Loctite where applicable.

Basic rebuild kits can be had for a couple hundred bucks and often come with pistons and other wearable parts. It’s best to talk about your options with your machine shop as they can help you choose the right rebuild parts for your engine. This is especially true if you changed any of the parameters of the engine, such as the bore and stroke. Planning is the key to a long and healthy engine life.

This tech tip is from the full book, SWAP LS ENGINES INTO CAMAROS & FIREBIRDS: 1967-1981.

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Sample Junkyard Pull and Buildup: A Turbo 5.3L

When building your LS engine, a lot goes into determining the level of the build, the parts, and the process. You ask yourself, “How much power can a stock long block take?” Well, when I chatted with Nate Shaw of One Guys Garage and he told me of his plan to build a budget corn-fed 5.3L LS engine, I decided I needed to find out for myself.

Nate allowed me to tag along with him as he took his engine to the dyno for fine-tuning at TPiS in Chaska, Minnesota. Nate said that he started with a virtually untouched 5.3L allaluminum long block from a 2005 Silverado that landed in a junkyard with 130,000 miles on it. Nate then replaced the head gaskets with an LS9 set because they have more layers than the stock LS gaskets. The LS9 set of gaskets provides more strength over stock LS1 head gaskets, especially in boost applications. Nate used ARP head studs, replaced the timing chain, and installed dual valve springs with new pushrods to increase his odds of reliably pushing the engine hard. The only other piece that Nate changed at the beginning was adding a stock F-body oil pan to clear the subframe in his vehicle. Beyond that Nate tells me the rest is bone stock and untouched. In this case, the subframe is from Nate’s Nova, but the chassis for the 1967–1969 Camaro and the 1968– 1974 Nova are virtually identical.

When it comes to purchasing decisions, Nate said, “Money could be saved on the intercooler as people have proven that the $100 eBay specials do work well. I chose a higher end unit as it fits my car better and has a little better overall performance. Also, the turbo is a name brand unit; it’s a perfect combination of power capabilities and size.”

Nate added, “E85 is the fuel of choice due to its higher octane rating, cooling properties, and is easily available in Minnesota.” Another area that Nate addressed is the injectors. He says, “I used low-impedance 95-pound Delphi injectors simply due to cost, but high-impedance injector prices are coming down. They do make things a little more simple as there isn’t any wiring when installing a driver box between the PCM and injectors.”

The first pull of the engine was, in short, disappointing and was far short of the horsepower targets. Even after fiddling with some of the tuning parameters, the guys at TPIS and CJ Tunes were frustrated at seeing the power leveling off at 5,000 rpm. A cam swap proved to be a much needed improvement in all areas of the dyno curve. The engine finally came alive and made a very healthy 824 hp and 718 ft-lbs of torque. That was all on a stock long block.

According to Nate, the key to reliability in LS engines is “E85 and a good tune. People really underestimate the strength of the stock parts when you have those two things. Naturally, it won’t last forever, but it works well when compared dollar for dollar to other higher-end engines. Carl from CJ Tunes is my guy and he works magic. I don’t trust anyone else to tune my engines.”

E85 hasn’t been around for long. Actually, it’s been around just long enough for the ingenious to see the potential for big power. Although I’ve heard some wild octane ratings ranging from 95 to 115, I have yet to find the definitive answer to that question. The problem with ethanol as it sits right now is that it’s not all that easily definable as gasoline. E85 that’s 85 percent ethanol and 15 percent gasoline could be equated as “race fuel,” which you cannot find at your average fill-up station. Ethanol (E85) allows for lower combustion chamber temperatures, which then allows for more fuel to be fed into the chamber and to be able to more safely run higher compression ratios. All of this equates to more power and longer use out of the long block. The downside is that due to the stoichiometric ratio, because more fuel is needed to run a engine when compared to gasoline, the fuel mileage you’ll notice is significantly reduced.

The original plan for the engine was to run roughly 20 psi and knock out around 900 hp, but as with all plans, they don’t always turn out. The sun set too early and Nate ran out of dyno time. Nate assures me that even though he wasn’t able to fully tune it to its full potential the 3,200-pound donor car is propelled into the 9s in the quarter-mile.

As far as future plans for the engine, Nate says an LS6 intake might gain a few more ponies, maybe as many as 20 to 30, but he’s fairly happy with the results and is pretty confident that this combination is a lot more fun than that old Silverado that was its first home. I couldn’t have imagined a better way to be put out to stud.

Written by Eric McClellan and Posted with Permission of CarTechBooks

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