Valve to piston clearance?

OP, maybe describe the pistons, milling, decking, and that cam you have in mind, and someone might be able to relate their measurements for a similar setup.

I have a spreadsheet for piston position versus crank angle. But the details of cam lift versus crank angle would be needed to work this on paper, plus a direct measurements off of the head for how far the valve sits above the head surface when closed.