Oil pressure-How much is too much?

Former team mate put an HV pump and new bearings in our motor. 90psi. It was working so hard, the electronics in the distributor would overheat, and the motor would die. After changing the distributor, the drive gear finally got chewed up due to the stress. He's gone, I rebuilt the motor, and it's survived a 36 hour endurance race, a 10, and a 7, with 50psi all the time running Castrol 10w30