Originally posted by "FordMan"
You can run up to 9:1 compression with no problems.
Where did you get the 400 h.p. number from ? That may be the case for your air cooled beast. A stock 302 with twin turbos would put out well over 500 h.p. at the wheels. I have read about it more times than I can remember and that is with a stock bottom end minus a different cam.
Slap in a good long block with two turbos and 800 + is easy.
I'm playing it concervative since I have heard no mention of an intercooler in all these posts yet. 9:1 might work if the charge air passes though an intercooler and the vehicle is burning race gas, but 8:1 would be less likely to detonate with a practical A/F mix and no intercooler. It would also give him the ability to go to higher boost pressures if he decides he wants to push it. If he goes to 9:1 compression he might as well give up on ever running more than 15 PSI of boost.
15 PSI of boost will optimistically give a motor around a 60% increase in power. Assuming that his 5.0 is only putting about 250 HP to the back wheels, then:
250 RWHP X 1.6 = 400 RWHP
The only way any 5.0 will ever see 800 HP is with a lot of high end racing hardware and over 22 PSI of boost. Unless you are made of money, there ain't nothing easy about that.
This is all based on basic thermodynamic principles and a good bit of hands on knowledge about ford and chevy small blocks.
Don't believe everything you read in a magazine, on the internet or what some guy tells you on the street.