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?