I think I may have asked this before, but what is the minimum head gasket bore that can be used on a Lo Deck with a 4.375 bore? This is a 511 biuld.

Cometic told me .015" to .030" back from the bore.

Cool. Cometic has a head gasket that has a 4.410 bore and a .045 thickness for my 4.375 bore. That's perfect and saves the head from so much metal removal. It will give .043 quench inline with pin and .031 with piston rocked in bore.

A 4.410 won't work with the Hughes CNC chambers; go with the 4.500.

No kidding. Ok, thanks for letting me know Brad. Saved me $200. I'm using the 4.500 now with a .051 thickness.

Yep, a 4.410 clears the bore OK, but the fire ring overhangs the edge of the chamber. I checked mine with both sizes to be sure.

Thanks again Brad, that was a good catch. Back to the drawing board.

I can still get 12.44:1 with the 4.500 gasket, close enough. It will require removing .045 from the head. The decks on these heads are super thick at .650".
What are engine builders now getting away with as far as the quench distance on large bores like 4.375 is concerned? .038, .040? and more importantly piston rocked quench on each side of the pin?