2011 Ram dually: best susp. setup, tie-downs & hitch exten?

I don't think you will need any suspension upgrades unless you have a really heavy tounge wt. Mine is bone stock and we pull a pontoon all the time. I do have dual trailer tires to lesson my tounge wt. I use factory Hitch which is pretty strong.

My slide does drop the side a bit, don't hurt anything. I have never paid any attention to it.