Ram 2500 trucks diesel or gas have 6000/6200 and 6500 RAWR which can leave up to around 2800-3000-3300 lbs for a in the bed payload all depending on truck selections.
The 3500 SRW has a 7000 rawr in the same axle with up to around 3800 lb payload in the bed.
And of course the 3500 DRW has 4 tires and a 9750 rawr for up to 6000+ lb payload in the bed.
Numbers above are a estimate as each truck depending on cab/drive train/options can weigh different after you get it home and add junk and goodies.
And non of the diesel 2500/3500 trucks will have any issues pulling their max rated tow ratings.