Weight of toy hauler

Probably your biggest issue would be how much of the 250's payload would remain after adding the tongue weight of the toy hauler. Toy haulers typically are heavy on the tongue to accommodate for toys in the back of the toy hauler. If you go light you are not taking that much tongue weight off the tongue. Add to the tongue weight all the rest of the stuff you will have in the truck and people, dogs, etc and determine where you are with payload. A 250 with a GVWR of 10,000 pounds is certainly a heavy duty 250 or I think you might want to check your numbers. If your truck is a diesel the 13,000 pound toy hauler would not be an issue towing, if gas you might be getting to the limits depending on engine and axle ratio.