My main concern was that it's a 3.73 axle gear ratio and if I load the 347THT 5'er toy hauler to the max GVWR, then I'd be over the max trailer weight specification for the truck by +900 lbs over.
Don't worry about that size trailer with a 3500 DRW truck with the diesel.
Dodge gave that truck a 9350 rawr so its good for around 5800 lbs payload in the bed.
The '07.5 Cummins is the 6.7 engine with the 68RE so it sure won't have any problems pulling a 14k gvwr trailer.
Trucks don't carry a GCWR/max trailer weight placard nor are they certified at a GCWR or for a certain trailer weight.
When the new '07.5 6.7 Cummins hit the streets lots of folks pulling commercially had to have one pulling heavy GN trailers. My neighbor lady came up with one for his and her hotshot company. She had it tagged for 38k gross combined which is a commercial requirement. You sure won't have any problem with a 14k gvwr rv trailer that may weigh closer to 12k-13k lbs gross.
