The gaskets or O-rings don't seal well to pits like they do to smooth surfaces.

What I would do
is clean them heads until you'd feel good about eating off the surfaces, including in the pits. Then mix up some original formula J B Weld, spread it in the pits as a filler, then after a few hours, take a straight edge of plastic or aluminum and scrape smooth the J B Weld that will be stiff but not hard yet, then let it cure a full 24 hours.

Only when the surface is smooth with no dips or high spots and no pits, with any JBW being fully cured, would I reinstall the intake.

I CAUTION YOU ... Do not get in a rush and try to install gaskets over the uncured J B Weld as the JBW will cure and then pull the gasket seals. You want as near perfectly smooth head surfaces and then the gaskets can seal as designed.

Edited by CrystalPistol (12/20/20 04:25 PM)

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Problems huh? Then Read THE Book. Signed: Natural Borne Neanderthal .