As it happens the 5er we just bought has a 14,000 GVWR, we are towing with a 2015 Ram 3500 crew cab, long box, single rear wheel, with Cummins diesel (not the HO). We packed the trailer up, added 4 6v batteries in the forward compartment, about 1/2 tank (50 gals) of fresh water and hit the scales on our maiden voyage.
Ratings for this truck:
GVWR 12,300
GCWR 25,300
FAWR 6,000
RAWR 7,000
Tow rating 17,000
Scale readings:
Steer 5,420
Drive 6,020
Trailer 9,940
Total 21,380
So you can see the truck weighed in 11,440, that's 860 lbs under my GVWR, but obviously a 10,000 GVWR wouldn't cut it here. The truck empty (with hitch in the bed) weighs in at 8,500 lbs, meaning the the 5er pin weight is 2,940, and the total trailer weight is 12,880 or 1,120 under the trailer's 14,000 GVWR. I am also 580 under the front axle rating and 980 under the rear axle rating.
As was stated, you can't shop by 2500 vs 3500 any more since the ratings vary by box length, engine choice and cab configuration. Some the 3500's according to the
Ram Towing Charts have GVWRs as low as 10,100.