understanding a low oil pressure 360

I set two FIA world records in two days at Bonneville. Doesn’t mean ****. I agree with @replicaracer43 that rod side clearance is not what’s causing this. That would be way down a long list of guesses at this point. Pressure is resistance to flow. Period. It’s not new news. Somewhere you have a big leak and it needs to be found. The relief valve in the oil pump, the lifters, oil galley plugs, those type of things would be high on the list to check first. Since you didn’t measure bearing clearance when assembling you absolutely cannot rule that out.