Well Proper Image, how is it going with your top end noise trouble shoot????

It seems that from ZEEKFTW's post, that deteriorating oil pan gasket particles clogging up the oil pump screen, or a oil feed passage to the head, belongs on your suspect list.

Maybe pull the oilfilter, cut it open & have a look see at the filter media, to determine what it's trapped, or if it's clogged up & gone into bypass & passed some of these particles on to the top end & clogged something up.

Or maybe the pump pick up screen is just partly fouled up with debris & flow rate is down, in which case a pan drop, cleanup & new pan gasket might suffice, if the top end hasn't suffered to much wear because of lube starvation.