According to the press release:
"Dodge Ram 3500 rear axles have a GAWR of 9,350 pounds. "
and:
[... the front axle ... ] "is rated at 5,200 lbs GAWR".
Looks like all 4x4 2500/3500's share a common front axle.
It also says the 4. 10 ratio ups the legal towing capacity by 2,000 lbs.