Good day. I have never checked the OIL PSI with a numerical gauge on any of my Three Styled JD D's or the two I assisted my neighbour in restoring.
I have ALWAYS checked the CONNECTING RODs bearing clearance with plastiqaue and removed SHIMS to decrease the running bearing clearance to the minimum on the connecting rods.
I have always ran the nut down (increased )two turns on the pressure control valve on the oil pump regardless of running history just as a matter of principal.
I have always removed the engine OIL pump inlet screen from below the FLY WHEEL and cleaned.
Installed a new JD oil gauge that reads L M H. With 40 weight oil and the coolant temperature gauge at 205 deg F the engine oil pressure gauge reads between the M & H at any Engine RPM.
I'm presently away for the winter and do not have any pictures nor operator manual or service manual: