Valve Drop and Piston to Valve Clearance

I'm no builder but sure looks like Max1196 used his ingenuity/creativity and found a fool proof method?
Well. It depends. "What if" the heads you're actually using are different from the valve spring seat to the valve seat? Also, there's the valve seats themselves. The heads you're actually using would have to be very close or the same on all respects in order to come up with the same or close clearances. Having said that, I think it's a purdy dang good idea.