Guys, the rear bumper w/o carrier is no problem. However, I doubt a 31" spare is possible with it. The stock bumper has a "crown" to it as it is a stamp formed part and that allows a little extra room for even the stock spare. Ours is perpendicular to the frame rails. I'll mount one up with a 31" and check. The stock receiver subframe is no problem with our bumper, so this would give you a class 3 hitch. As far as something that will allow you to mount a swing arm carrier later, I really don't see a way to do it. The parts are just too big and bulky to make removeable. I'll check back and let you know. -Steve.