Well I have to agree with Iroc, for that much hp you should probably go with an automatic, and 4.11's arent' going to do squat for you. You'll just be waisting horse power. Superchargers are great, but I think twin turbo will be your best bet. Although I have heard good things from prochargers. I would go with bowtie or vortec heads though, they tend to flow better. But if I was you, I hope not to piss anyone off here, but I would go out and get a super chevy magazine, look at the articles and see what other people are doing. We can give you numbers and advice all you want, but that way you have something to actualy lay your eyes on. But if it's small block you want, then listen to Iroc, havn't seen any thing but great advice from him.