The big problem with the stock axle bearings was getting the preload right. This was adjusted by pulling the passenger side axle and using a special tool to reach in and turn the thrust button in the differential to make it longer or shorter, then reinstall the axle, remeasure end play, and repeat as needed. About as much fun as screwing a porcupine. Since you are replacing the stock open diff with a Sure Grip you will need to go through this process at least once if you use the stock bearings (if you're lucky). Use the Moser bearings you are comfortable with...