It's called having these issues in the past first hand. You also have to remember his gaskets are .060 thick and there are .045 and .030 thick intake gaskets available if removing .080 isn't enough. Without knowing exactly how much milling was done to the heads this matter requires an educated estimate. .080 seems about right from my experience also. I've had heads milled myself in the past where a .060 intake gasket resulted in the holes being off by the same amount as his are without gaskets. I was able to use .045 gaskets but a .040 would have probably been a the ideal choice.