Did it go from having no quench to a real quench area with the milling? If so, I'd think that would have something to do with it needing less ignition lead.
Did the BSFC numbers improve, too?
This is what I was getting at. .040 compressed head gasket?
Now I need to pin those needles, got to feel that heat Hear my motor screamin while I'm tearin up the street
