How much can valve head OD be cut?

Hey DF: That was the plan, but then I figured out how deep the notches would go down the sides of the bore; the notch depth for the cam lift I want is such as to get very close to, or even into, the travel of the top piston ring at TDC. So it is a ring-travel-to-notch interference issue. So the options are:
  • smaller valves, or some combination of that plus other methods, to eliminate the bore notches
  • lower lift to make the bore notches less intrusive
  • larger pistons and bores.... (But my next piston choice that does that failed in a couple of ways.)
Yes, sir, that is another option, and I have been looking at iron heads today: I have to dig into the Speedmaster 1.92 flows versus the other options. The LA-X is another choice.... but they are out-of-stock all over right now, of course!
In that case id go with the smaller valve. I dont think that much will be lost from 2.02 down to 1.88 valves