I currently have a 2002 Trans Am with a cracked block. Don’t feel too bad, because she had 275k miles on the original LS1! It has been in the barn for a few years and I have decided it is time to put it back together now.

I am planning to build a LS3 based 6.6 L naturally aspirated engine to later turbo. I am in the beginning stages of spec’ing out the engine internals. I would expect the engine to be putting out around 500 hp b/4 the turbos.

Here is what I have decided on so far:

GM LS3 block
3.9” stroke crank
LS3 heads

Currently looking for suggestions for pistons and rods that will fit with the 3.9 stroke, along with bearings and rings.

Are you dead set on a ls3 block if not how about a 6.0 or 5.3 especially for a turbo build down the rd

I am set on the 6.6 L displacement. Just something that is old school traditional in a T/A. I want to be able to drive it for many years and like the additional cylinder wall material available in the LS3 blocks over the LS2 (honing during future rebuilds). I was thinking fairly mild with the turbos, but that might be a couple of years down the road. Something like 10 to 15 psi. I really want a lot of torque down low in the RPM band.

I like the way you think! I will have to see how salty an LS7 block is now.