I never clay or solder to check piston clearance.
1st, I measure piston dome with piston edge flush with cylinder. This base measurement will be used again and again, for dome volume and deck.
2nd, with rings installed for tension in the cylinder, I align the piston in running position and shove it into the head. Again measure the piston dome in that position. Subtract the dome height and the results are piston to head clearance with “0” deck.
3rd, install piston and cylinder one the engine with the base gasket u might use, snug down the cylinder and measure the piston dome again.
Using the dome measurement and arithmetic u now know your deck clearance and total piston to head clearance when u add it all up. I also use the Bruce Anderson compression ratio measurement. I use a digital caliper for my dome measurements.
