^ Back from the dead!
Also an update from me, my growling went away after I replaced my clutch and had to remove the driveshaft to drop the transmission. Perhaps I relieved some kind of factory slack, alignment, or bolt torqueing issue?
I *think* I tightened up everything back the same, but I did not use a torque wrench. (Yes, I've checked the bolts repeatedly since) No growling for 2 winters now.