302 heads

For your HP goals of 325 ish HP, any head will work. I'm not a fan of the 302's on ANY performance oriented build. Also, I don't think the piston sticking out 0.013 would work well with a closed chamber head (measure and see).

Many years ago I did some track testing of a lightly home ported 302 and a home ported J head (both by me) on my nearly stock 318 with a 150 N2O shot (this was in Colorado, thus the slow times). The J heads ran 13.9 on the 150 shot and the 302's (on the same motor about 2 weeks later) ran ~14.4...a half second slower....after that the 302's were sold.