Mr PRH and Mr Pittsburghracer, have y'all ever tried your best J heads on a large bore block? Like 4.185" to 4.220" ? What kind of HP do you think those heads could support on a properly prepared short block?
Sorry I’m zero help to you. I haven’t played with a stock small block head since the 1970’s. My buddies Magnum heads stirred my curiosity some but there are the Mopar aftermarket head that came on the crate engines. BPE had a set of small valve heads on his 340 and ran I think 9.60’s
