There's a lot of factors (lunchbox, Detroit automatic, selectable, t-case ranges, etc) but I would go with front as you're more likely to need front end traction when climbing than in the rear, as weight distribution always favors the back end on an incline. The front end can pull the rear up some obstacles at lot easier than the rear can push the front over them. You just have to account for some understeer in tight corners and to avoid turning at full lock if possible. It really depends on what kind of terrain you're going to be on. If there's not much articulation involved, go with the rear.