How to Swap an LS Engine into Your Classic Car

LS-swapping your classic Camaro, Chevelle, or El Camino is an incredibly rewarding experience that many owners do to modernize their ride while keeping the vintage looks that made them fall in love with their car in the first place. Because these swaps are so common, there are a ton of resources out there detailing how to perform the swap on various vehicles. Plus, there is more aftermarket support for LS swaps than maybe any other engine swap.

However, all this information isn't always a good thing. No matter where you look on the internet, you'll find conflicting opinions, hard-to-understand tech jargon, and confusing write-ups. This makes actually swapping an LS into your ride harder than it needs to be.

In this article, we'll be going over the important parts of an LS swap and what you should keep in mind when performing them. This isn't a step-by-step installation guide, but more of a general guide to get you started.

What is the Chevy LS Engine?

The Chevy LS is a series of pushrod, 2-valve V8 engines that started production in 1997 and is still used in vehicles today. They've long been a popular high-performance engine swap for enthusiasts wanting to make a ton of power.

There are a wide variety of LS engines, but here are some of the most important ones and the year they were released.

• LS1 (1997)
• LS6 (2002)
• LS2 (2005)
• LS7 (2006)
• LS3 (2008)
• LS9 (2009)

There were also a variety of LS-style engines created by Chevy under the Vortec brand for use in their trucks and SUVs. Some enthusiasts use these as swap candidates because they have iron blocks and a smaller displacement. Plus, many of the LS accessories bolt onto Vortec engines with no problems.

How to Choose the Right LS

For many enthusiasts, choosing the right LS for their build comes down to budget. If you're looking to make maximum power with an infinite budget, going for a more modern LS with a larger displacement is the right move. LS3s are incredibly popular swap candidates because of their increased displacement compared to LS1s, LS2s, and LS6s.

However, LS1s and LS6s are still popular swaps because of their availability and cheaper entry point. The ceiling may not be as high, but you can still make 300-500 horsepower easily on these engines.

The main driver for many LS swaps is budget. If you're going to do most of the work yourself, you can afford to get a nicer, higher displacement engine to start with because you'll save money on labor later. If you don't have a huge budget and you're looking to keep costs low, starting with an LS1 is a great choice.

It's also important to do some research and determine what LS swap accessories or kits are available for your car. If you're trying to swap an LS9 into a car without and adaptor plates, wiring harnesses, or other important components available, you're going to spend more money on fabrication and custom wiring than you would otherwise. The key to a good LS swap is understanding your budget and what you can do with it.

Sourcing Your LS Blocks

There are a few different ways to source an LS engine for you swap. The easiest and most obvious way is to buy a crate engine. Chevy realized just how popular LS-swapping cars had become and started offering LS crate engines straight from the manufacturer years ago. While not the cheapest option, it guarantees you a high-quality starting point. You won't have to worry about unknown mileage, previous owners who skimped on maintenance, or regular wear from years of abuse.

Another way to source an LS is to find someone selling one on sites like Facebook Marketplace or eBay. A quick search and a skim through the results will generate hundreds of potential swap candidates. This is a cheaper route than getting a crate engine, but beware deals that seem too good to be true. It's impossible to know where these engines came from and the life they had before ending up on an online marketplace.

Buying an engine off someone online can be a great way to save money, but always do your research and vet each engine thoroughly.

The final way you can source an engine is to pick one yourself at a junkyard. This is easily the cheapest, but also the most questionable method. These engines are complete unknowns that have been sitting in junkyards and salvage yards for who knows long while being exposed to the elements. These engines can be incredibly rusty, missing essential components, or damaged. If you decide to pull an LS from your local pick-a-part, be aware that it's most likely going to take a lot of work to get to where you want it to be, if it ever gets there at all.

Choosing the Right Engine Mounts

Because you're swapping an LS into a classic car, there's a good chance the existing engine mounting points won't line up. To get around this, you're going to want to get a set of LS swap mounting plates for your specific car. Luckily, LS swap parts and accessories are incredibly plentiful and people have put them into almost everything so you shouldn't have any trouble finding vehicle-specific mounting plates. A lot of aftermarket mounting plates are also adjustable to allow you to move the engine forwards or backwards for more clearance.

If you're not sure why adjustable mounting plates are important, here are a few things to keep in mind when orienting your engine in your engine bay.

• Weight Distribution
• General Engine Bay Clearance Issues
• Crossmember Fitment
• Oil Pan Fitment
• Exhaust Clearance

If you're unable to find engine mounts for your ride, you'll want to get in touch with a fabricator and work with them to create custom mounting plates. This is definitely more expensive and time-consuming, but without proper mounting plates you won't be able to LS swap your car.

LS Swap Transmissions

Luckily for enthusiasts, there are a wide variety of supported transmission options for the Chevy LS. So, you should have no trouble finding a transmission to fit your needs. You don't even have to use a Chevy or GM transmission. However, be sure an adaptor plate exists if you decide to go with one that isn't originally paired with an LS.

LS Swap Cooling System

The cooling system is another important area to consider when swapping an LS into your classic. Most professionals recommend going for a twin fan setup with the largest available radiator that fits. This is especially important for cars that are running superchargers or turbochargers.

There are a ton of available LS swap-specific radiators to make this job as easy as possible. Keep in mind that you'll also need other cooling accessories like an LS water pump and coolant lines to complete the swap.

LS Swap Accessory Kits

While an accessory kit may sound a little vague, they're an essential part of a good LS swap. These kits usually include all of the pulleys, brackets, and hardware needed for the swap. They also include important components like the water pump, power steering pump, power steering reservoir, A/C compressor, and more.

There are various brands that make high-quality LS swap accessory kits, so it's all about finding the one that fits your needs and budget.

LS Swap Wiring and Electrical System Upgrades

This is considered by many to be the most challenging part of an LS swap. While you could save money and try to integrate old, potentially damaged wiring with a brand-new LS wiring harness, we recommend you just start from scratch. There are a variety of LS swap wiring harnesses and ECUs available from a variety of manufacturers. Find one that works for your ride and go with that.

If you're swapping a car without an available aftermarket LS swap harness, you're going to need to modify an existing one to suit your needs. This is a tall task for many experienced mechanics, so it might be best to find a shop that does wiring and have them do it. You can always do it yourself, but one small fault can cause your car to burst into flames, so be sure you know what you're doing.

Fuel System: To Modify or Replace?

Upgrading your fuel system is also a great idea if you plan to LS swap your car. Most swaps make considerably more power than the factory engine, so you'll need more fuel to supply that new engine. We recommend you replace the your stock fuel tank with one that's designed for a full EFI setup with an integrated fuel pump. You should also upgrade all of the fuel lines to accommodate for more flow.

Is an LS Swap Right For You?

The Chevy LS swap has been a popular choice for enthusiasts chasing performance for years, but that doesn't mean it's right for you. If you decide to LS swap your classic, be sure you do plenty of research and planning before starting any work.

Check out various forums, Facebook groups, and other community meeting places if you have any questions. Many community members are more than happy to help answer and will even give you first-hand advice and accounts of their own LS swaps to help you in yours.

Thanks to our friends over at Backyard Barn Finds for providing us with the basis of the information in this article!