How much weight can your dodge 3500 carry with a 20000 gooseneck trailer.?

Your Dodge is rated to carry 2000#, therefore you have to adjust the load accordingly if you have the leeway to do so ie. loading a 15000# machine on the trailer you can move the machine toward the truck until you reach the maximum load on the vehicle, leaving the bulk of the weight on the trailer axles. Wheel scales are necessary to weigh the axles when shifting the weight. You are only allowed a total of 2000# on the truck by the licensed weight.