I saw this somewhere and dont remember where but the best way to put it is this : Speed is a question of money, how fast do you want to go?
what your looking at with a stock set of heads and stock compression and a little hotter cam and a nice intake and carb and a good tune up is maybe 400-450 horsies, maybe. compression is hp up until the point of detonation put about 10.5:1 pistons in there about .060 over with some good gas in there you might hit 500. maybe. oh yeah a good set of headers with a good exhaust.