I had a problem with the
oil pick-up tube in one of my old GT350's. I swapped a used 289 HiPo engine into a 350 I had bought with a blown-up engine. I didn't have the funds at the time to rebuild it, but thought since I had to pull the pan anyway to put the Cobra "T" pan on it, I'd at least put a new
oil pump in it.
I installed a new HV
oil pump, HD shaft, and BOSS 302 pickup tube (larger ID). When I fired the engine up, oil pressure was fine at idle (around 45#), but, when I revved it, instead of going UP, the oil pressure went DOWN. Turned out to be a hairline crack in the new oil pickup tube (sucking air) I had purchased from Ford. I installed another one, and the problem went away.
Regards,
Jeff Burgy