Ford 8.8"
The Ford 8.8" rear axle is found under many F-150, Explorer, and Ranger platforms. Ring and pinion fitment depends on spline count (commonly 31-spline on later trucks), ratio, and whether the axle uses a limited-slip or open carrier.
Match gear sets to your carrier break and intended tire size. Re-gearing the 8.8" is a common upgrade when moving to 33"–35" tires on half-ton trucks.