Just check the oil pressure by taking out the oil pressure switch(above the oil filter)and running a manual gauge. Engine started up with 20 psi At 1200 rpm and worked it way down to ten psi in a matter of seconds at the same rpm. If I'm not mistaken if the pump was working well shouldn't it be pumping more psi from that point and then it would decrease through the slop in the bearings if there was any. Could the oil pump be screing up..... Maybe loose pickup or the spring messing up. Or a defective oil pump? What would be the signs of a bad pump? What I want to know is my assumption correct? Shouldn't this pump start up cold should be putting out like 45 to 60 psi and run at like 30?

Im reading the same psi at the top as the bottom???????????
I'm going with defective oil pump.
which would be better if this is the case. High volume or high pressure????? oil pump?
Kenny