I have difficulty using an EAZ lift weight distribution hitch to connect my travel trailer and truck. To help in connecting the torsion bars, the truck/trailer connection should be raised about 3" us...
So, how much of that 6" is the the sagging of the rear end? If it's about 3" and you raise it another 3" to snap up the brackets, sounds about right to me..
I use the same brand hitch and that's about what mine does. Got an electric tongue jack and that makes it easy.. :)