I've converted 389 heads to screw in studs with guide plates. Oil delivery galleries were blocked at the deck of the block to accommodate pushrod oiling to the Comp Magnum Roller Tip Rockers. I have 60psi at the gallery next to the distributor base, but no oil showing at the pushrod/rocker while manually priming the engine at 275rpm. Is it just that the rpm is too low, or might there be a different problem ?
Sometimes i never see oil up top unless i rotate the engine some while priming (by hand), just the pumping of a couple lifters will let you know if it's there. Sometimes i see it dribbling out of a few. I always worried until someone gave me the "rotate it while priming" advice, and then i got a lot more up top.