Chev 216 Oil Pressure

[Ken Thomas]

Hi, My 216 engine has been completely reconditioned, assembled and painted. I have just fitted the external oil piping to the bypass oil filter etc. Thought it would be a good time to check for leaks and also ensuring there was oil to the rockers. I made up a drive to operate the oil pump with an electric drill down through the distributor mount in the block. I am alarmed that at 900 RPM input to the pump there is 40 PSI on the test gauge (used two gauges same reading). Increasing the RPM to 1500 I get 42 PSI. and I assume the relief valve has opened. Max RPM of a 216 is 3200 RPM giving 1600 RPM at the pump. Normal maximum engine RPM would be about 2000 RPM again giving pump RPM at 1000
Now the max. setting of the relief valve is 15 PSI at 2000 RPM according to the manuals.
I have a new Melling pump fitted. Is it possible that this pump could be set up for a later series engine with higher oil pressure requirements?
Of course my other thoughts are that the relief valve is working but stuck up or restricted some how. As any investigation of the relief valve means dropping the sump - new gaskets etc, I thought I would run this past you folks for your opinions.