Thank you for the input Fish. I pulled the cover and it sounded like it was coming from the head so I pulled the spark plugs and turned it by hand. Noise still there, kind of a double squeak. Definitely not the head gasket, something in the crank or cylinder itself, maybe the counterweight. Not worth tearing the crankcase apart to figure out. I think I'm going for a crate motor replacement. Far less effort and I know it will be fixed.