I did find a 55.2 Chevy truck shop manual on line. So far I have found a reference in it that says the pressure relief valve on the pump would limit the oil pressure to approximately 35 psi and in "specifications" at the end of the chapter defines Oil Pump Pressure as 45 psi with no reference to rpm for both 235 and 261 engines.
It’s nice when the official information contradicts itself.
