Per the door sticker and your scale ticket, it looks like you have 1,780# left over for tongue weight with a weight distributing hitch. Your hitch rating is likely below that, so it will be the limiting factor. Unless I'm missing something, I don't see the GCVWR (gross combined vehicle weight rating) on the sticker - you should be able to find it in the manual or towing guide. That number minus the 5,020# total truck weight from the scales will tell you what you have left for GROSS weight of the trailer.
When you quote trailer weights, are these empty or the gross weight ratings off the stickers on the trailers? If curb/empty weights, forget those. Use the GVWR for the trailer and calculate 12% of the trailer GVWR for a loaded pin weight.
We towed a 26', 7,200 lb. GVWR travel trailer with a 1/2 ton V8 SUV and it handled well. The gas V8, though a good powerplant, was a limiting factor on grades and in the mountains. Just make sure you use a WD hitch with anti-sway and get everything set up properly.
Happy - and safe - camping!
Rob
