Building a 383 for boost. Going to use the new Trick Flow heads with the CC306 and not sure who's turbo setup yet but will prolly use a T76 with whoevers I go with. May have a turbo setup made locally. Anyways. Just wondering what sort of compression I should go with. I will be using JE pistons, H beams and a 4340 crank. Also what is the stock CC on the combustion chambers of the LT1 heads? Thanks

 

For a turbo setup I would highly recommend going with 8.5:1 compression. Since I assume you want to most out of your setup I would highly recommend swapping your CC306 cam for a custom turbo cam.

 

Depending on where you live and race, I agree that 8.5:1 sounds right.

 

8.5:1 sounds about right for low to moderate boost. If you plan mega-boost, I prefer even lower. Definitely no more than 8.5:1, especailly considering that turbos usually use small cams.

BTW: CC306 is a crappy choice for a turbo.

Rich Krause

 

Go 8.3-8.5 CR, and ditch the CC306 like Rich said. You will bleed all your boost away with that cam. The 76 is a great turbo and you will like it very much. As far as the stock CC for LT1 heads its 58CC.

Jose