Boarder Line Low Oil Pressure

How do you know? You do know "Some Engines" are built loose right?
It may have been built for thicker oils.
Sending a sample out would also be on the list when you swap to a heavier oil.
The report will tell you a lot.
Look through an older Chilton's manual. Like the big pink book we called it. I think it's like 65 to 72. Somethin like that. I have one somewhere. Compare ALL the other us makes bearing Clearances to Ford. Ford had consistently greater bearing clearances than all the rest. Also, if you've ever been around an older original Ford with any of those old engines from the past that had some mileage on them, you can hear them rattle. Perfectly normal for them. They just ran and ran and ran and ran.