I have pulled an assortment of trailers with the following "Suburbans" or Yukon XLs or Escalade ESVs ( 1997, 2001, 2003 and 2007 and all essentially 1500
models) The 1997 and 2001 had trailer packages but really the packages were more for extra cooling capacity rather than significant suspension improvements. The 2003 and 2007 had no claimed trailer packages as such. I only ever used WD hitch assemblies. And like you I continued to used the same trailer and WD hitch through a vehicle change. In 2007 the factory trailer hitch assembly was mounted integrally into the bumper assembly for an outside appearance improvement but then the ball height increased substantially. Several people's postings on this topic have mentioned ball height. I am curious if you have dealt with the ball height?