doing a build on a 70 440hp debating on running 10-10.5 comp vs 9.5-9.8 do you think I will notice a diff in the power or anything else besides needing high octane fuel? Is the higher comp. worth the cost of the race fuel as far as more hp goes (just a weekend warrior run hard put away clean)

Are you using aluminum heads or iron? With aluminum you want 10 or higher and wouldn't need race gas. Iron I would stay about 9.5.

well If machine shop is not to crazy on heads I will run the 906s I was thinking alum. but $$$$$$$. Do you think I will notice diff in performance in compression diff

Maybe a couple tenths at the most if that much. For a street car I would keep the comp in the pump gas limit. But if you build good quench and run the right cam you can run in the 10's with iron heads. I run 10.0 on the 440 in my 63 with 906 iron heads. I have quench as I use the KB quench pad pistons and I can run on 92 pump with 38 total and no ping at all. It has alot to do with the setup such as cam and quench and cyl pressure. If you dont have good quench I would keep it around 9.5 for iron heads and 10.5 with aluminum. With quench I figure about a 1/2 a point higher. Ron

what pistons would you recommend my build is was thinking kb hper. or seal power 2355s

1970 440 hp 6pk
40 over
mr 6pk #3 cam
stock manifolds
906 heads

I dont mind running race gas if I can burn more rubber