5th wheel hitch....
We have had two Trailair pin boxes on to other 5th wheels and had a B&W turnover ball with the companion 5th wheel hitch. The B&W is the best static 5th wheel hitch system we have owned, we had a Reese and a Valley/Huskey. For the money I like the B&W best. However we have owned two Trailer Saver Air ride hitches and we have the Trailer Saver now. When we ordered out 5th wheel in June we deleted the Trailair pin box and went with the Trailer Saver (TSLB2H 32,000 lb) capacity. We have the standard pin box and have no chucking or noise at all. The Trailer Saver does as the name implies. I believe the Trailer Saver takes a tremendous amount of stress off the frame, and I'm sure you are or have read about the frame issue. The TS air ride hitch is pricey but you can move it (TS 3) from truck to truck. It fits in the standard bed rails. I used my TS 3 in 4 different trucks 3500HD's and a Chevy Kodiak 4500. We have over 3,800 lbs of pin weight and the 5th wheel rides very well, we remove nothing from our counter top and secure no funiture at all. Just another idea for you to consider. The cost of your Truck and 5th wheel deserves the best Hitch. By the way you have a awesome Truck and the Duramax/Allison is a proven combo. GBY...