Yeah, I'd say that truck is plenty big. Hook a trailer to it and you wouldn't have a problem hauling 5 Yamahas. If your looking at only hauling one quad you could get a half-ton short box and get better fuel mileage while your at it.

 

I had a Nissan Frontier 4 cylinder and hauled 600 lb quad in the back and one on a small trailer, now this was on flat land and only 25 miles round trip.

 

The 5.4 is a good motor, looks like a retired work truck?

 

I haul 3 with a jeep with a straight 6 gonna do 4 this year.That ford ought to handle 4 on a trailer one in the cab.You might buffalo your spouse with "WHY I GOTTA HAVE THIS TRUCK" but you aint gonna fool us!Just go buy it...she will get over it before she gets mad again!
ESCAVADER

 

Those 4.0 motors are pretty strong. A budy of mine has three 4x4's with the 4.0 I6 one with 270K miles and he tows a bobcat with it!!! Fords 4.9 I6 is pretty tough too for a six cylinder.