<strong>1. </strong>We got a used donor axle to start the project. Note, there are a few differences between the axles spanning the last decade or so. There are three disc brake 9.75-inch axles that grow progressively wider. These are ’99 to ’04 models, ’05-up, and the Raptor versions. The later versions use 3-inch-wide springs, while the earlier models use a narrower pack. The early axles also use slightly smaller brake components.