That would be nice but I have not bought the 5th wheel yet . All I can do is go by heartlands website on the weights . So how do I come to that conclusion . only sticker I see says tire loading 3897
The door sticker on the truck usually would say Payload = x,xxx lbs. Could be 3897 is the payload - it's in the ballpark. For planning purposes, you can estimate pin weight of 3,200 for a 5th wheel with GVWR of 16,000 (20%). Add the weight of your hitch, bed liner, bed cover, tools, pets, passengers and anything else in the truck. Sometimes the actual pin weight is more than 20%; sometimes less. Depends on floor plan, options, and what you put into the trailer. You won't know the actuals until you have the trailer, load it and take it to a scale.
You'll likely be close to the payload limit.
We towed our 16,000 lb Landmark for 4 years with a 2011 GMC 3500 CC Longbed 4x4 SRW. The payload was about 4,100 and we were about 200 lbs over. Our Landmark had an actual pin weight of 3,700, driven by washer/dryer and generator up front along with a full basement. It pulled fine, rode level, and handled well. Traded it in last year for a RAM DRW.