John C Garage 1.4 Inch Drop Shackles for 2011-2021 GM 2500HD/*3500HDFeatures JOHN C GARAGE 1. 4" Drop Shackles for 2011 2020 GM 2500HD *3500HD These shackles provide exactly 1 and 3 8 of an inch of drop in the rear. 100% Drop In, No Modifications Required Leaves pinch weld factory, minimizing the likelihood of rust developing. Almost level look when used in conjunction with slightly raising the torsion bar. (1") Will work in conjunction with airbags, allowing you to support heavier towing Heavy Duty, Thicker Metal,