Found this at https://www.enginelabs.com/engine-te...lve-clearance/
Is it a good way to do it?
For the dial indicator method, follow all the previous setup steps except placing clay on the piston top. Again, use solid lifters, install the rocker arms and set zero lash. Rotate the crankshaft clockwise until the degree wheel indicates the Number 1 piston is at 10 degrees ATDC on the intake stroke. This is the crank angle where interference is most likely to happen--not at TDC or at maximum intake-valve lift. At this point, the piston on its way down and, depending on the cam lobe profile, the intake valve is trying to chase it down. Mount the dial indicator on the cylinder head and position it over the retainer of Number 1 intake valve. Set the dial indicator to zero. Make sure that the plunger on the dial indicator has plenty of range to move up and down. Use a small screwdriver or pick to push tip of the rocker arm downward until you feel the valve contact the piston. Observe the dial indicator to determine the actual piston to valve clearance. To measure the clearance on the exhaust valve, rotate the motor clockwise until the timing wheel is at 10 degrees BTDC on the exhaust stroke. Again, this is the crankshaft position most likely to see P2V interference as the piston moves up and draws a bead