If you are talking about the Montana line with a SRW and concerned about staying below your trucks GVWR you probably going to be close or over on most of the Montana line. Loaded ready to camp you find that your dry pin will increase between 600 to 1000 lbs depend on how much you load. Then put people, hitch and stuff in the truck you will lose 400 to 600 lbs of the trucks payload.
Here is a site that does a good job and guess what your pin will be using dry weights.
http://towingplanner.com/Estimators/...0&lw=14640&a=3
Still have to account for the above pin weight but also the weight you put into the the truck.
Some exceptions would be toy haulers and front living room are little harder to predict.