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:
Speedmaster PCE281.1773: Cast Iron Cylinder Head Small Block Mopar 318/340/360 | JEGS
cast iron speedmaster LA style head with 1.92 intake valve, 1.625 exhaust might work for you, unless your committed to aluminum
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!