I might be cheaper and easier to swap the rear axle. What do you do with you rango?(Off-road, Daily Driver,Race truck) is it 4x4? what gear ratio do you have? the reason i ask is so i could tell you what axles i would look for. the durango's stocks axles arent that great if you are doing anything other than daily driving, with out mods anyway. but this would give you a change to go to a stronger axle lower or high gear ratio, plus you can get your Disc brakes out back. Hope this was some help.