what will it take to make dana 44 axles out of a scout fit in a xj?

 

The rear is narrower and would need wheel spacers as well as new spring perches and shock mounts. The front is a passenger side drop and you would need to swap your transfer case and reroute the exhaust then fab up the four link and track bar mounts. And it's also narrower than your stock axles as well. You could have a shop replace the tubes on the front and make it a driver drop and have custom length shafts made and then fab up the mounts. It would be a lot of work for not a great deal of strength upgrade. The front is also a low pinion so you would loose a bit of ground clearance.