(Best) copper head gasket and offenhauser aluminum heads

[Lhead]

Originally Posted by Tim Ayers

L head,

I'm in the process of doing the same. I'll found the 1/8" shaft stone set from Harbor Freight works well for this job and are very cheap. I was using some carbide bits, but these stones are working well with the copper gaskets.

Approx what dia are you opening up to and are you doing all the small holes or just the rear
Thanks