LS Engine: King of the Late-Model Swap

The LS engine is likely the most recognized late-model engine. Some may even go so far as to say it’s the most praise-worthy V8 platform to date. Why? Because it’s reliable, versatile, and can be built for superb power. Sure, with the right builder, this is technically true for all engines. But throw in the fact that the LS platform is abundant and affordable, and suddenly you have an engine that’s in a league of its own.

What is an LS Engine?

Now, I’m not going to get into any redundant details here. LS swaps are nothing new and most enthusiasts are very familiar with the platform. (If you’re not, check out the helpful video below for an introduction.) So, in the interest of telling you something you might not already know, we reached out to our friend John Potucek of Keystone Automotive, who himself runs a 5.3 LS engine 1973 Chevy Nova.

Potucek shares with us a key point that many builders may be unaware of — the LS platform actually consists of a family of engines with a variety of sizes in terms of displacement.

“The ‘LS engine’ comes in many varieties,” explains Potucek. “4.8-liter, 5.3-liter, 5.7-liter, 6.0-liter, and 6.2-liter, in iron and aluminum blocks. Basically, ‘99 and newer GM V8s all fall in the LS family. I say basically because there are a few exceptions. As far as the engine codes, there are many (LS1, LS2, LS3, LS6, LQ4, LQ9, L33, LR4, LH6, LC9, etc…) but they all fall under the LS family and most parts are interchangeable,” he explains.

This aspect alone adds credence to the versatility of the platform. If you think about it, this characteristic is something that can be compared to with the Small Block Chevy (SBC). In fact, this is why in the years before the LS, the Chevy 350 was crammed into everything built under the sun—particularly when budget and simplicity were of utmost importance. And, in hindsight, when you consider that the LS is basically a replacement to the SBC, it only makes sense that GM would ensure the new platform would feature many of the same strong points as its predecessor, along with the characteristics that bring it to the next level.

Hit the Ground Running

So, I won’t beat around the bush. If simple is what you’re after—SBC all day. Carbureted platforms will always win that race in the short run. But still, the LS engine is the better choice all around and there are many reasons why.

First, the blocks are more thermally stable, which really helps deliver consistent performance and reliability. They also feature 6-bolt mains, which makes for a stouter engine when compared to the 4-bolt main 350. Plus, out of the gate, you have fuel injection and multi-coil ignition, which helps put these in a higher league than the traditional small block. And did we mention the aftermarket support??

Fuel injection is a big deal, though. And, truthfully, to start from scratch building a fuel-injected SBC is going to put you right about in the same price range of simply purchasing the LS. There’s another elephant in the room too, and that is stock performance. Building a fuel-injected SBC on the same performance level as a LS engine is going to stretch your budget.

Disclaimer.

Now, this is a very fast-and-loose statement and it’s not going to hold water in a lot of arguments. (Trust me, as a Mopar man, even my veins were popping out of my forehead as I wrote it.) I mean, much of our current conversation (and even future conversations) concern LS engines sourced from boneyards. And, truthfully, the exact same thing can be done with SBCs and you’ll probably get a better deal. That’s not even factoring in used or reconditioned speed parts, which can be had for a steal, or those donated by a buddy to the cause.

In other words, I understand that there are a lot of variables that can come into play when scrapyard parts are on the table. I also know that not every build will come up with the same price tag.

HOWEVER, let’s compare crate engine costs. A Chevrolet Performance 420-hp, fuel-injected 350 is going to set you back about $7,500. A Chevrolet Performance 6.2 with 430-hp is going to run you almost exactly the same amount. Pop in the stronger mains and better thermal efficiency and there’s a clear winner here. I know, I know, we can argue for days when specific applications and situations come into play — so, by all means, give us your opinion in the comments.

Power Builds

Now, naturally, we all have the urge to reach for the bigger engines on the list—the 6.0L and 6.2L. After all, there is no replacement for displacement, and plenty of fine examples of rides bearing these bigger LS engines can be found all over the nation. A personal favorite of mine is Lucky Costa’s 1966 Chevelle, bearing the 6.0L fitted with a roots blower to make a ton of fun power. There’s also the infamous 1969 Daytona Charger movie cars that Dennis McCarthy built for Furious 6, sporting 6.2L LS3 V8s, rated at 430 horsepower.

Though sensible options, Potucek chimes in to remind us that these are not the only LS engines worth building for power. “My favorite platform, by far, is the L33,” he says. “This is often referred to as the ‘factory race engine’ within my group of friends and here’s why: It’s an aluminum block 5.3, flat top pistons with gen4 internals and good flowing heads—basically an LS6 head. This engine is special because it was only made for three years, 2005-2007, and was only available in extended cab 4×4 1500s with VIN B, the H.O. engine package. So, it’s pretty rare. This is the engine I run, and currently feeding 26+PSI of boost (again on stock 300k mile internals). Some people are scared of the aluminum block, thinking it’s too weak, but that’s false. The 5.3 has nice thick walls and is constantly being used in 1000-hp applications,” he asserts.

What to Consider

We’ll be discussing a lot more about the LS engine in the future, but for right now we’re going to leave you with some food for thought. Since most people reading this are either interested in what it takes to pop an LS engine in an unnatural platform, or are already in the process of making it happen, you likely already know it’s not simple to just throw in an engine like this.

Engine management is going to hit you in the wallet, as will mounting solutions for the engine and chosen transmission. You will also need proper cooling and fuel delivery systems, just to get you started — all of which we will be addressing soon.

Stay tuned and weigh in down in the comments. We want to hear about your LS builds!