No oil pressure at idle
did you have all oil holes lined up with bearings? I believe the oil goes to the mains first then to the sender but dint quote me on that. something could be restricting it, how was the bearing clearances. I believe my 340 with high volume pump is like 40 psi at idle and goes up from there. My bearing clearances arent lose though.
Alot of new bearings are coming through defective no oil holes i had to file oil holes into a 5.0 ford rod bearing recently. Well it was 2014 LOL!