Need advice
Dave
I stroked my LS1 on my trans am last year to a 383. All forged internals and a cam spec'd for nitrous with stock 241 heads put down 453/432 through a auto after its initial tuning. After break in it probably would have made more and if it was a six speed it probably would have made around 465-470 and even more with a good set of heads. Drive train loss isn't gonna be much in a vette so your goals will be easy to reach.

