leadertape,
I don't think you are missing any plugs because if you were you would never see 50 pounds of pressure. You really do not need more than 40-50 psi at cruising, and if you have 20 or so at hot idle your fine. You probably have big clearances, which is not a bad thing - to a point. I actually set all my FE's up with a little more clearance than factory, and the
oil pressure usually is in the 20 psi range at hot idle, and around 50 or so at speed. Look at it like this - if you have your engine set up and your
oil pressure is 70 psi hot, this means your
oil pump is pushing like crazy to try to move the oil but the oil is not moving very fast. If the oil was moving fast, the pump would not build up so much pressure. The critical issue is not really pressure, it is making sure your bearings are constantly supplied with fresh oil. You want the oil to get into the bearing and get right out. You do not want it staying in the bearing too long - it will get too hot. The bottom line is I think people put too much emphasis on oil pressure when the real issue is oil flow, and high pressure does not necessarily mean high flow. One more thing - do you have your idle set at about 800 RPM? I've seen some guys complain about their oil pressure being too low at idle and come to find out that the only problem was they had their idle set at about 400 RPMs. That's too slow for the pump to work.