I'm considering buying a new Ford Transit van when the become available in Canada. I would get one with the ecoboost engine, but unfortunately the Transit 250 has a towing capacity of 5400 lbs., wh...
The Transit is supposed to have available the 3.5L Ecoboost, which has plenty of HP and torque for your needs. If the van is not being given a higher tow rating, it can't be for lack of power. I would try to find out what is the limiting factor: the transmission, the rear end gears, the cooling, the hitch receiver attachment, or something else? Some of these things can be cured with aftermarket mods quite easily.