That's what I figured...no quench & I can hear the pinging already.
So if I mill the heads .015-.020, compression goes up too...and there's real no benefit?
I thought I saw this info somewhere and can't put my finger on it, but what is 0.010" equal to in CC's?

btw...I was thinking about one other measurement I made that I did not publish here. I put a straight edge across the head, and measured 0.073" with a feeler gauge to the flat of the chamber. If I take that value, subtract the quench dome of 0.039", that's 0.034" (0.011" less than the solder test). I wonder if the solder didn't crush down all the way. That would place quench at 0.054"...still 0.014" less than ideal, but better.

Is grinding out the head overhang a typical approach to increasing the CC's? I assume leave the quench area alone.