Cooling Difference in Aluminum heads?

intake closes @ 37 abc,
No it doesn't; that is the .050 tappet lift number. In other words the valve is still open; .050 times the rocker ratio, less that portion lost to pushrod angularity.I could guess the valve is still open close to.067 with 1.5 stamped arms. You cannot start building compression until the valve is right on the seat. Fully closed.