The LS family is a series of engines that are actually really similar to each other. The architect of the Gen III and Gen IV Chevy V8’s is extremely similar. The Gen IV’s are supposed to have a slightly stronger block, but not by much. The main difference between the engines in the LS family is the displacement, intake, camshaft, and various small details. The LS2 and the LS3 have a lot in common. But, the most obvious difference between the two is the displacement.
The LS2 has 6.0L of displacement, and is technically was the first Gen IV Chevrolet engine. The LS3 on the other hand has 6.2L of displacement, and is also Gen IV Chevrolet engine. But I’m sure you’re wondering if there is other things that are different between these two, other than the displacement. So, lets dive in, and compare LS2 vs LS3.
LS2 vs LS3: Cylinder Heads
One of the biggest horsepower gains most V8’s have is with aftermarket cylinder heads. Luckily GM was actually really good at developing cylinder heads when they designed the LS engine. Throughout the years Chevrolet continued to perfect the LS heads. The LS2 heads were a slight step up from the LS1 heads.
To no ones surprise, the LS3 heads are better than the LS2 heads. I am unable to find definitive flow numbers for both heads. But, from browsing around forums and asking some engine builders, it seems like bolting LS3 heads onto an LS2 will gain you about 20whp+. A 20whp gain is pretty impressive considering your swapping OEM parts with more OEM parts.
These gains are due to changes in the intake runner length, size, and shape. Small things like shape can have a large affect on how air flows into the engine.
LS2 vs LS3: Intake
Just like the LS1 vs LS2 debate, the later engine has a slightly better intake manifold. This is the case from the LS2 vs LS3 debate. Chevrolet increased the intake manifold flow by straightening out the intake runner, and optimizing the flow path from the intake manifold to the cylinder heads.
This all adds up to a slightly better intake manifold. The manifold’s increased flow helps bump power up about 5 horsepower compared to the LS2’s intake manifold.
LS2 vs LS3: Displacement
We briefly covered the difference in displacement at the beginning on this article. The LS2 has 6.0L of displacement, whilst the LS3 has 6.2L of displacement. But, the has the same exact amount of stroke. Their bottom end is actually near identical, but the Chevy gave the LS3 an extra 12 cubic inches of displacement. “How?” you might ask.
Chevrolet upped the displacement of the LS3 by giving it a slightly larger bore. The LS2 has a bore of 101.6, whilst the LS3 has a bore of 103.25mm. As I mentioned before, this gives the LS3 an extra 12 cubic inches (.2L) of displacement. This helped up the horsepower from 400, to 430.
The increased bore also helps make the LS3 much happier to revs. It revs up much quicker than the LS2, and generally responds quicker to throttle inputs. The increased bore also means slightly higher RPM potential. The increased potential for RPM’s makes the LS3 a favorite amongst high performance engine builders.
LS2 vs LS3: Cost
When you think of picking up a used LS engine, most people think of either an LS1 from a Camaro, or an LM7 from a Tahoe. Why is this? Because both those engines are pretty old, and pretty abundant. Both of these things make them dirt cheap. But what about the later LS engines like the LS2 and LS3?
The LS2 was released in 2005. It was the new Corvette base engine, as well as an optional engine from the 05-06 GTO. Because of its smaller production, and the fact thats its newer, the LS2 is typically much more expensive than an LS1, but isn’t really worth the premium to most enthusiasts.
The LS3 was released in 2008. Much like the LS2 before it, it was the all new base Corvette engine. The LS3 was also used in the 2010 to 2015 Camaro. This means that the LS3 is much more abundant than the LS2. But, because of how new the engine is, they’re still fairly expensive.
So yes, the LS2 is cheaper, but not by a huge amount. Honestly for how much better the LS3 is I would personally just save up for a little longer and go with an LS3 instead.