I was initially getting p-v contact with my build but that was due to the lifters being fully pumped up and the pushrods being slightly too long, once I got shorter pushrods I could assemble the rockers and slowly rotate the engine so the spring pressure would bleed-down the lifters.
Wouldn't spinning the oil pump pump the lifters back up? I've also been searching around and i've seen a couple people mention they ran cams slightly bigger than mine on a stock Magnum short block with no P-V clearance issues.
I guess if I really want to get this right I gotta hit the junkyard and grab 2 more lifters to convert into solid testers.