I have found that with the Melling M57HV that most of our engines have about 30 to 40 at a hot idle and 70 to 80 at 3000 to 4000 rpms and then levels out. The
oil pressure has to do with many things in the engine and the bearing clearance has a lot to do with that. If you have fairly tight clearances, say .002 or tighter this would contribute to this problem. With the tighter clearances it would be best to run a 10W30
oil. If your clearances are .0225 to .0035 and you still have this kind of pressure you may want to look at the relief spring in the pump. I would try the 10W30
oil and if it brings it down to 60 at a hot idle and say 85 or so at higher rpms I would truck on. Good luck with this. Thanks, Keith