Gotta build ANOTHER engine.

I've never worked with dialing a Magnum engine, but I used to change the tip of my dial indicator to a flat tip, and place it on the top edge of the hydraulic lifter. You could also just use a solid lifter, or they make tools that slip into the bore like a lifter to make it easier to dial indicate. Goodson sells them, I believe .

Oh i'm talking about checking actual piston-valve clearance, I already degree-d the cam with a degree wheel using a dial indicator on the edge of the lifter just like you describe and it came out spot-on with the 0 advance keyway on the crank sprocket, I made sure I was lining up the correct dots on the sprockets too. Cam is a custom-grind hydraulic roller from Racer Brown.