Actually had a set of new main bolts and new head bolts i used from my father when he worked for Dodge dealership all his life. Hes pretty puzzled too as hes built MANY mopars from stock small blocks to 8000 rpm hemis and hes never seen these symptoms. Seems if bearings were the issue, id have plenty of evidence in the filter and would have low oil pressure at hot idle but its still the same as when assembled.