X O U or J heads on a 416?

RustyRatRod said

I'm curious about something. Have you ever weighed a bare casting both before and after porting?

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After porting, one pc bronze guides, hard seats both intake/exh, spring seats cut and .045 ish milled... they were maybe 2 lbs lighter. I don't know for sure but I can weigh them agaisnt some bone stock 70 castings I have. You can definitely feel the difference if you pick one up, but they're still iron. If they were ever to be that light 'like aluminum' they probably wouldn't last long once the engine warmed up LOL.
You won't see really good numbers out of a j head till it's about 175 CC's..or better. When I say good numbers I mean real strong low lift numbers as well as a decent Peak you can get a pretty decent Peak but have crappy Lilith numbers and that tells you your bowl is wrong or the valve job n lower angle isnt right/large enough . You can get 240s to 250 without getting into too much work.
Mainly stick to the classic 30 45 60 75 angles.