Differential or wheel bearing???

Well your hot bearing is a good indication. Unless you have a dragging brake.
I'm fairly certain it's not the drum. I rebuilt those right when I got the car, and I'm not getting any of the normal symptoms. I've just always assumed that the rear end noise was the diff, until I read something recently that made me check into the wheel bearings.
have a 7.25 to do in a few weeks too. Its out and on a stand so its easier to do.
I plan to pull it apart, then order the necessary bits.
Take lots of pics for me???