I am having an issue with my 2011 Denalli HD and my Super Glide receiver that I use for towin my fifth wheel. I have a mismatch of almost 6in from my pin box to my receiver. This becomes an issue as I have to extend the fifth wheel to a point where it almost becomes unstable when I back in to connect. Wondering if there may be a way to lower the truck in some way. I have tried other new fifth wheels to hook up and I have the same problem. Wondering if GMC has addressed this problem, evidently the newer trucks and fifth wheels have an issue. Help!!!