Bob and Jean Webb

    the pressure relief valve may not be the problem. these engines do not behave like todays cars. you could have enough wear on the bearings to cause the oil pressure to start falling. you also could have wear in the oil pump which would lower pressure. you need to have close clearances on the bearings and the internal parts of the pump. this was covered in the repair manuals. I have known engines that needed bearings at 30K to 40K miles. these alpines ran at a lot higher RPM’s than todays engines. series 5 alpines had a 4.22 gear in the rear compared to the 3.89 in other series. at 60 mph engines were turning rpm’s in the high 3’s. that’s twice what my chevy and GMC are running at the same speed. check the relief valve first but if it’s ok, check the bearings.