It goes through the frame underneath the rear, right above where the diff tubes are. I'll remember eventually. Has large threads like it might hold a rubber bumper, I just don't recall that.
Wait... Ummmm... Exhaust hanger (bare with me here), hanger perhaps?
Where the hell is @RacEoHolic330 . Maybe he remembers.
It's a dark image but it looks like there might have been a rubber bushing on the end of it.