I'm thinking the height of the side oil hole/gallery height interface especially if lifter to wall clearance is healthy. I'm just thinking out loud but we are losing alot of PSI & not thinking that the crank/bearing clearances would be altered significantly from running/not running esp if you are running full groove mains (but I ain't sure on this/just speculating) but with FG mains I'd think the passages (saddles to crank innards) would be open all the time.