In reading the Big Inch Cadillac book, the early 76cc(??) heads were not cast for EGR. My understanding is this meant not having that in the combustion chamber that needs to be closed up. And the head apparently lighter than a head with the EGR casting. Not sure how much lighter.Are small port heads the magic for some builds??
Isn't this going to be the same issue with machining down large chamber heads down for higher compression than 8:1?I would not use a thicker head gasket to lower compression unless you verify proper quench area.
Id rather have a 10.5:1 with proper quench than a very detonation prone 9.5:1 due to improper quench.
These engines seem very timing sensitive to begin with.