Do you have a deep pan on it??High volume pumps are not good for standard oil pans,too much oil up top, not enough down low.try a standard pump.or a weaker spring.(large nut on the back side of the pump.It is possible to do it on the car.Fresh engines will have higher oil psi.If running a 15w40, 20 w 50,etc,A thinner oil will also help.10 w 30.put some miles on it,break it in.did you change it after the cam break in??should to get the assy lube out of the oil.
How are you reading the psi. manual guage or the factory stuff.factory stuff could have an error.Make sure you have a good filter on it.I have had fram's burst at 90 psi.use a good filter,wix,napa,purolator.