Low oil pressure?

the O. P. does not have 273 rockers or shafts, he has stamped rockers. Dave Hughes said that as the rpms are up from idle there is a steady flow of oil up to the rockers, and I believe him, think about it, as the cam spins faster the flow is virtually full time. when a 340 shaft is installed correct, the oil outlet holes face down, and are partially blocked. If the shafts are upside down, the 16 holes face up and are wide open, lowering oil pressure