Years back we used a Ford cube van with a 460 cube motor. We would tow a trailer behind it to carry 2 cars. It pulled fine and all but the 4 mpg you get would bleed you dry with todays gas prices. Box trucks just push to much air. If you are thinking enclosed trailer and want to save your transmission, buy a V-nose trailer. Also much better on gas. Especially if you like to drive 70 mph+. I have yet to take my own advise on the trailer, but have towed a friends with about a 4 mpg improvement over my flat nose Pace trailer. Unless of course money is no object in which case buy the diesel toterhome.
Chris howard