I just called Texas Speed this week and would suggest you do the same.
I am planning on installing the same setup LS2/4L70E out of a Trailblazer. They recommended a 228R with 114 LSA with stock heads and and LS2 manifold to keep the powerband in the lower rpm range versus the upper if you go with the L92/Ls3 heads. With good headers, ls2 car intake, good tune and the recommended cam you should get you over 500hp. This cam is mild so a bigger would yield better results.
Here is a link to the cam
http://www.texas-speed.com/p-1158-te...pring-kit.aspx