These 1/2" tall axle relocation plates are great for moving your axle slightly forward or backward while correcting pinion angle at the same time.Our relocation plates can be used with or without degree shims. We include two different locating bolts which will allow you to use these with or without shims. .The relocation blocks will allow you to move the axle 1" or 1.5" forward or backwards, depending on which hole you use. Or, if you don't think you need the offset, you can use the middle hole and keep your options open. .It's an easy install: simply slip the relocation plate between your spring perch and your leaf spring and tighten your U-bolts back down. You will need to drill a new hole in your existing leaf spring top plates (or use a set of our WFO Concepts 2.5" wide leaf spring plates with offset holes!) to line up with the center pin offset of the relocation plate.