The LS Engine Family Explained

The LS family tree stretches far and wide, starting with the LS1 in 1997. The LS engine family has since become a favorite crate engine option for those wanting to upgrade what’s under their hood. The reason? GM’s LS crate engines are affordable, reliable, lightweight, and (relatively) easy to integrate into any vehicle.

While there are over 30 engines in production, here are the most commonly integrated options from the third and fourth generations of the LS family:

Generation III

The List:


LS1 Engine

Replacing the LT engine family in 1997, these small-blocks both share a 5.7L displacement - just with different heads and intake. The LS1 first appeared in the 1997 C5 Corvette as the aluminum LS1 V8, followed by the LS6 that first appeared in the 2001 Corvette Z06. GM increased the strength of the block of the LS6 and put in a MAP sensor and a higher flowing intake manifold.

Most Generation III engines have sodium-filled valves with a higher lift camshaft to increase power. However the heads, intake manifolds, and camshaft on the LS6 are definitely an upgrade over stock LS1 components. If you already have an LS1, then sourcing these parts from a used LS6 is something to consider.

Generation IV

The List:


At its introduction in 2005, the LS2 was offered in the Corvette, GTO, and the SSR roadster. It was also the standard engine for the Pontiac G8 GT, with its larger displacement equaling more power.


LS3 Engine

First placed in the 2008 Corvette, the LS3 features 430 hp from a 6.2L engine, making it the most powerful engine in Corvette history. With larger bores than the LS2 and strengthened casting to support more power, the LS3 is offered in the Pontiac G8 GXP and the 2010 Camaro SS. The L99 version is equipped with the Active Fuel Management Cylinder deactivation system.


LS4 Engine

The LS4 is a 5.3L 303hp engine used in front wheel drive applications like the Chevrolet Impala SS and the Pontiac Grand Prix GXP. The LS4 includes an aluminum block and a flattened water pump to accommodate the transverse mounting position found in the Impala and Grand Prix.


LS7 Engine

The LS7 is standard in the Corvette Z06, and its 7.0L displacement (427 cubic inches) means it’s the largest LS engine offered in production vehicles. Unlike other LS engines, the LS7 incorporates a Siamese-bore cylinder block design to accommodate its 4.125-inch bores. With 505 hp and lightweight components like titanium rods and intake valves, the LS7 is primed for the racetrack.


Bred for racing and built for power, the LS7.R and LSX are primed for speed. Both based on the LS7 engine, the LS7.R (also called the C5R) is aluminum while the LSX is cast iron. Originally developed for Grand Am racing, the LS7.R is not for sale to the public. But for aftermarket use, the LSX is an affordable design that has been proven to support over 2,000 hp.


LS9 Engine

The LS9 is the granddaddy of the LS family and is the most powerful production engine GM has ever built. Featuring a 6.2L supercharged engine with a monstrous 638 hp, the LS9 uses roto-cast cylinder heads and a 6th gen 2.3L supercharger. Built by hand at the GM Performance Build Center, the LS9 uses a dry-slump oiling system.