I don't have the specs for the 2004 but I do have 2005 specs which should be identical.
It doesn't specifiy which axle ratio is used for these, but they came standard with a 3.73 so most likely that's what the specs are based on:
Reg Cab 4X2: 10950 lbs
Reg Cab 4X4: 10450 lbs
Quad Cab 4X2: 10600 lbs
Quad Cab 4X4: 10100 lbs
Source: 2005 Dodge Ram brochure