Workin g on a 1941 Cadillac, motor runs beautiful. When engine warms up oil pressure at idle will drop to 4 lbs. I do have an external gauge on it. You have to really rev it to get up to 25-30 lbs. Tried a stiffer spring in the oil pump relief valve and it did not make a difference. I installed an external pressure oiler and the oil came pouring out of the holes that are right next to the connecting rod journals on the crank shaft. Is there supposed to be any kind of restrictor in those holes. The motor runs great. No rod or main bearing noises. Lifters are quiet. I also checked out the oil pump and that seems to be in spec. Any suggestions would be appreciated. Thanks very much. Charles S.