The F350's capacities are greater. There was some discussion not too long ago on here about the rear axles. Some said they were exactly the same but if I remember right it was proven that the axle in the F350 has a different part number and has slight bigger components (shafts and bearings) than the F250. I have no idea why you would buy an F250 with these newer models. It used to be because the F350 had a ride that was too harsh but that's not the case now. They both ride the same, if you buy an F250 you are just getting a de-rated one ton and so many people realize this mistake when they go rv shopping and find out the pin weight on the trailer is too much for their 3/4 to but is well within the F350's capacity.