After seeing Loves302Chevy post, I see where your quench distance is too big (.021 + .041 = .062").
So he is right, you need about a .021 inch thick head gasket. That will bring the quench distance down
to .042 inches, nearly perfect.
I'm using these SCE copper head gaskets. You don't need to o-ring the heads. Just use something like
Permatex Copper Spray-A-Gasket. Search for it on here Grumpy should have several posts about using
it. It's actually turned out to be cheaper in the long run, I've had the heads off twice now. So I'm on my
3rd time using these gaskets.
This gasket is .021 inches thick and has a bore of 4.160 inches.
NOTE: The price of $48.90 is each, so double that for your engine.
https://www.summitracing.com/parts/sce-p111521/overview/
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https://www.summitracing.com/parts/ptx-80697
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Note the changes are in RED numbers.
Advancing the cam timing 4° is not the best way, but it's easily doable.
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