I agree with everything these guys said, and I may be overstating the obvious, but I do have a few tips. First, measure and record everything before you order a new box. Put a micrometer on the shafts and count the splines. Measure the mount hold distances and note if its a 3 or 4 hole mount. Also pay very close attention to the input and return line sizes and if they are metric or standard, old flange or o-ring connectors. I recently endured a 3 week nightmare attempting to simply replace the steering box on my YJ. The PO had upgraded it with one from a 77 Waggy, or so he said. 9 boxes later I finally found one that worked. Moral of the story, check all your specs, and make sure they match before you buy a new unit.