Well a little disappointed in myself :( but these were all most 20 year ago now.
found my notes, I didn't right the specs for valve to piston clearance down. notes only said that i use a .020 steel shim head gasket and that i had to grind off the shelf of the pistons valve relief to get proper valve to piston clearance.
From memory(o Boy) i do remember that one of the valve hit the valve guide before it hit the piston top.
When you get ready to check valve to piston clearance you will have a light checking spring installed onto one cyl intake and exh valve. you will rotate eng over a little at a time stopping to push intake and exh valves all the way to the guide(bottoming out) when you hit the piston, you install a dial indicator on the valve stem and keep nudging you eng over and check clearance. when it start to grow instead of get small. that's you Valve to piston clearance.
note this is with your cam pushrod and rocker arms installed.