Originally Posted by Vicr
No. The 22k comes from the combination of the axle and tires. The 18k axle is a Dana 80 with 4.30 differential ratio and the 22k is the Dana S130 axle.
The thread on another forum no one uncovered the axle and diff change. We do know the cab sticker on the 17 model 31ul says 228 inch wheelbase from memory, but it actually measures 190. Ford allows the end manufacturer to change the wheelbase (longer or shorter) to suit their needs.