I use .035 minimum piston to head clearances which includes measure every piston at TDC the edge of the piston and block on the cam side with that piston pushed over tight to the cylinder wall by using a small narrow screw driver blade push down between the other side of the piston and cylinder wall to force that to piston rock over which should lower that side down and measure it and then switch sides with the screw driver to the cam side of that piston and rock it back the other way to make that side come up all the way, that is the highest edge on that side to use for the .035 minimum piston edge to head clearances. then do the other side of that piston and use the highest measurement to get your P to H clearances
You can check two pistons at TDC without moving the crankshaft also