Compresstion Help

[car9fan]

Originally Posted by Rev

When I ran 351W heads, 59.5 cc's, pistons down 0-.005" in the bore with 2.7cc valve reliefs and .049" compressed gasket we figured 9.5/1 CR. That's with 4.030" bore and a 302 crank. Hope that helps a little.

Rev

Thanks for that info. it does help, Ronnie

[1989GT]

is worth about 15% net power at the crank.

I'm sorry Jeff but I'm not buying 15%. I mean maybe I'm completely wrong cause I know you have quite a background in this but I figure more like 3-4%. So a 400 motor would gain about 12-16 hp with a full point raise in compression based on 3-4% or 60 hp based on 15%. I can't remember all the specs on my DSS 306 but with the P heads I'm making about 9.8, 10:1 based on factory tolerance.