Truck- 2011 RAM 3500 SLT SRW, 6.7 CTD, 4WD, short box
GVWR 10100 lbs
CCC (as per door sticker) 2846 lbs
RAWR 6200 lbs
FAWR 5500 lbs
Ram really missed the mark using a 6200 rawr for a 3500 srw truck.
Your getting good info on using the truck and rear suspension help.
That 6200 rawr is the lessor of a tire/wheel/axle/rear spring pack.
Higher rated tires and wheels plus rear spring pack help of your choice.
The axle is a AAM 11.5" rated approx 10800 lbs and is the same one in the DRW and 2500 trucks. No issues with it carrying heavy TCs.
Your trucks front axle may not carry more weight so weighing the trucks front and rear axles after loading it all up is a good idea. Then figure what higher rated tires/wheels and rear spring pack is needed.