Math isn't mathing

Hitch weight (or pin weight) is roughly 20% of GVWR. 20% of 14k is 2.8k, which is slightly more than their claimed 2610.  Depending on how they balanced the load (assuming they loaded one to full GVWR) they may have weighed the pin at this actual figure, and/or they are providing the best estimate for what weight the pin would have. Use this figure to guesstimate what the load would be on your truck.  Your truck's Payload will be reduced by all passengers, gear stored in the bed, hitch, etc.  Make sure you'll still have ~2600lbs left for the pin weight.  However, be careful to check your truck's Rear GAWR.  Almost all the pin weight (95%--just assume all) will be on the rear axle. Weigh the truck alone to get your rear weight (load on rear axle when unloaded) and subtract this from the GAWR to get your max available load capacity for your rear axle.  Hope that helped--we are new to this ourselves, but, my math background, hours of research, and experience as a long haul driver helped me grasp all this over the last couple months.