I currently am running 5.13 94 third members in my 97 tracker (to replace my 4.63 gears). the rear swapped in without any problems. the front did have a 22 sline outputs as opposed to my 97's 26 spine outputs. All I had to do was swap the spider gears from the 97 into the 94 member. its as easy as doing a drop in locker install. I could have also used 22 sline shafts from the older truck...but why go down in spline count?
To swap the spider gears, I just marked the location of the left to right ring gear adjusters, unbolted the carrier retainers and removed them(being sure not to move the adjusters. While having someone hold the reainers in place I pulled out the carrier. If the adjuster rings don't move, the gear location should remain the same. Open up the carrier and swap your spiders(be sure to mark the ring gear so that it gets bolted up in the same location). Finally put the carrier back into place while keeping the adjusters in place and reassemble.
I hope this helps