I AM underpowred for a big tire.But I know a guy who built a 509 bbc(mine is 496) 16:1 comp with 365 heads and about a 850 lift cam.Made 1,050 hp on alky. That's what I hope to do one day.Don't think I want to try it on a stock block,though. Thanks for all the calculators guys.They are very handy,and I never can find stuff like that on my own.