Best method to ascertain how close to "0" deck you are, is still to mock the engine up prior to final wash and prep, then Mill the block "equal & square" from the mains to where you want it for deck clearance.
It's nice if your shop has a "BHJ Block True" or similar fixture attached on their surfacing machine, to actually correct the 90 degree angle at the same time as the deck ht.
Mopar blocks are unfortuneately "the worst" in that area, especially after a million thermal cycles in 100,000 miles.
You may also wish to check out some Lunati "voodoo" series cams also. The smaller stuff works awesome, but not sure if they still carry them in the catalog.