The weight cops on here will tell you you need a F550 to tow that. Reality is that you will overload the factory suspension and tow ratings more than likely but look at the difference in the 2 trucks you are interested in. Same frame, same brakes, same axle, heavier springs.
Will you be above the book weight? Probably
Can you beef up the rear suspension as long as you don't go crazy with the weight and be fine? Yes.
Man if Ford is smart, they will offer the Eco in the new '16 HD pickups to replace the anemic 6.2l. They'll sell a lot of them for this type of use!
