I used the GKN kit with perfectly fine results. The clamp went into the next to last tooth if I recall correctly, and when tightened with the proper clamps was solid.

Did you see this picture from RealOEM and confirmed if you have axle "A" or axle "B"? A I think was for early builds.

__________________
2018 Ram 2500 6.7L Cummins 68RFE
19k miles -Bright White/Black - Big Horn Sport - Crew Cab Short Bed
2013 X5 35D (CEO's) - Born on 5/17/2013 -
82k miles - Alpine White/Cinnamon Brown/Premium Pkg, Sport Activity/Premium Pkg and Sound/20" Style 214/Running Boards