Well after so much back and fourth about getting rid of my 2011 srw truck I finally pulled the trigger yesterday and bought a f350 drw. Way more truck than I needed as it has the high capacity tow pac...
I suspect your 5500 has 19.5" wheels and bigger diameter tires, the 350 I bought has 17" wheels. Honestly I avoided the f450 because I didn't want the higher cost of those tires and knew I didn't need it.