It is best to maintain between 10 and 15 lbs of oil pressure for every 1000 rpm. If your pressure readings are on the low side the TA 1502 Adjustable Oil Pressure Regulator may be just what you need. This key part replaces the relief valve nut and spring (next to the oil filter). Turning the adjuster screw in will increase oil pressure and backing out the screw will lower the pressure.  Recommended for any oil pump re-build and much safer than using heavy weight (color coded) springs. Fits 198-215-225-231-252-300-340-350-400-430-455.

NOTE: Does not improve pressure at Idle, proper pump set up and TA 1510 will improve pressure at idle.