Almost time for the machinist!

It's all about tolerance stacking with 50 year old parts
if valves are sunk pushrod theoretically shortens by 2/3
larger valves and higher seats just the opposite
just put it together and see if there is some play when you push the pushrod down
not a race car or fast action cam you are good to go
then cut the tops off a couple of old valve covers and observe lifter rotation and oiling,
you can do the oiling check when you spin the oil pump with a drill IF you have the oil holes in the cam lined up - rotate the crank slowly with a breaker bar and observe- remember cam is at half speed of crank so you might have to go around twice to hit oil- if you do not hit oil then find out why before you fire the motor