Ford 8.8 Differential
Out back I went with a 98 Explorer 8.8. This piece is the code D4 axle which means it has the limited slip Trac-lok , 31 spline axles and 3.73 gears. I ordered up new seals, bearings , and a short side axle from Rockauto . The trick here is the Explorer has an offset differential so one axle is shorter than the other. So you shorten the long side axle tube to the same length as the short side and replace the long axle with a short axle. I also picked up a Ford Racing Trac-Lok rebuild kit and freshened it up. As for the rear disc brakes I went with Power Stop Brakes . There is not much to choose from as far as upgrade brake kits or performance brake kits for the Explorer 8.8.
As for shortening the axle tube , "The Fabrication Series" has a great video on YouTube.