scott, hope you installed a deeper oil pan , too easy to pump out the 4 qts into the engine and have 0 oil pressure
the oil pressure reading with an electrical sender is relative. you either see a reading or you don't. install a mechanical to verify the actual pressure
high pressure can be :
incorrect sender/ incorrect ohms value
the oil pump, oil pump reliefe valve
wrong oil filter, clogged oil filter
spun main bearing ,spun cam bearings