Except for the idle it sounds an awful like like a worn down rod bearing to me. The camshaft could push forward if the thrust plate came loose, but I don't think it would cause an oil pressure drop until the cam was almost half the thickness of a cam journal out of place exposing the oil feed holes in the cam tunnel. And at that point you would probably hear the cam gear grinding into the timing cover and the oil pump lever. But there would be no way for it to slide back into place on its own when it cools down. Sorry to say there is no way I would run that engine again until its sorted out.

I've completely stripped a 360 in my challenger down to the crank without pulling the block from the bay. Wasn't easy, but when you don't have a shop or an engine hoist you do what you have to.

Start from the outside and work in until you find the issue. Could be as simple as a broken or backed off rocker allowing a tappet to travel up out of its bore, exposing an oil passage.