If you intend to wheel hard enough to break things, I would tow it to the trail head and have stuff to be able to limp it back to the trailer. Pretty much what Curious Hound recommended. Alternatively, if you wheel so far from civilization that the only way to get back or help is with an In Reach or a sattelite phone, you might want a pretty extensive list of suppliesas well. If there is more than one vehicle in a group with the same vehicle, share the load so everyone isn't so loaded down with spare parts and fluids.
If it is for breakage because things happen, you don't need as much. Since you mentioned a Dana 28, bearings and a spare hub for it wouldn't be a bad idea. Maybe some spark plugs/wires and a couple lug studs incase you break some. You are looking for things that will repair it enough to get you back to where you can either limp home or get a tow. Bailing wire, duct tape, a pich tool or two to clamp off a brake or heater hose. Things like that. Recovery gear as well incase you are so hard broke you need pulled out. From what I hear, you don't want to pay for a company like Matt's Off Road Recovery to come and get you. While they provide an important service, it is a very expensive service.
