The 48 216 in my 3100 gives around 14psi cold and drops to around 6 or 7psi warm. At idle it's around 6psi and at speed around 7psi. I run 15w40 oil.
I'm guessing your mains are less than 0.003" clearance? If so it's definitely possible the cam bearings are worn. Did the new oil pump make any difference? You might try testing the pressure with a another oil pressure gauge to verify the pressure.
moparguy, the 216 and early 235's have pressurized oil to the crankshaft main bearings, cam bearings, front timing gears, dipper nozells and the valve train. The dippers on the rods provide lube oil for the rod bearings and the subsequent oil mist lubes the cyl walls, pistons, cam lobes, dist shaft and all internal surfaces of the engine.
You might find this video interesting (once it gets past the opening lol).
Riding the film
