Extended Notes: 1. Measure rear axle tube before ordering. Some 4" axle models with dual overloads will require 4068. 2. Rear lift options will not fit dually applications. 3. If driveline vibration occurs, order either transfer case drop or indexing kit available in optional accessories. NOTE: 122606 Transmission drop kit will only replace the OE bracket #52121938AA 4. 102009 Rear brake lines will not fit 2012 models. 7. Exhaust modification will be required for dual rear shock kit 122009.