The axles are the same. If you look on the drivers door jamb, you will find a sticker. On that sticker find the heading "axle", under that will be a code. The codes are below to tell you what type (open or limited slip) and ratio you have.
Explorer
Door Code
41..... Open 8.8"…...... 3.27
42..... Open 8.8".…..... 4.10
43..... Open 8.8"…...... 3.08
44..... Open 8.8"…...... 3.73
45..... Open 8.8".…..... 3.55
46..... Open 8.8".…..... 3.73
D1..... L/S 8.8".…....... 3.27
D2..... L/S 8.8".…....... 4.10
D4..... L/S 8.8".…....... 3.73