Like I said earlier, 5er's don't mix with most 1500 because of the lack of payload. His GVWR is 6700 lbs, subtract unladen vehicle weight and thats how much stuff (people, fuel, hitch, and pin) it can carry. Just a comparison mine is 12,200 almost double the payload of this pusher. Jim's GVWR is 14k which is more than double the payload. Simply put that truck just can't carry the weight of most 5th wheels.
Even if you were to use the RAWR of 3900 lbs I believe your max would be exceeded at roughly 1k lbs. Hitch alone will weight 200 lbs. Not many 5er's with a pin weight that low. IMO a nice bump pull is in order, lots of nice TT well within this trucks specs.