The word "super" typically inspires confidence and reassurance whenever it is used. It also pre-qualifies something that is of great value or excellence. Four wheelers know this, and they expect a product with "super" in the name to be just that. For example: "super" precedes the word "duty" in the name badged to Ford's long-selling 3/4- and 1-ton pickups. Regardless of its marketing origins, Super Dutys are well known for their unparalleled hauling ability and flexible work-truck configurations. In this case, the word super works perfectly because the Super Duty has earned its reputation as the dominant platform throughout much of America's towing fleets and utility service companies.
With so many Super Duties roaming our nation's roadways, it is no wonder that an owner is always looking for ways to distinguish his truck from the rest while enhancing the vehicle's performance. Custom wheels and bigger tires are always a good starting point, but how big a tire do you need? Typically, tire size is governed by the amount the truck is lifted. How much can you lift a pickup and still retain the vehicle's stock ride quality? With Fords, there is really no incorrect answer here, thanks to Donahoe Racing's strict product guidelines which mandate that all suspension systems they produce ride better than stock. Donahoe has been manufacturing suspension systems since the early '80s and now offers everything from a 2-inch leveling kit to a balls-out 10 1/2-inch system for Ford Super Dutys. The owner of our donor truck decided he wanted to run 37-inch tires-not too big for everyday driving, and definitely enough of a metamorphosis to make a two-year-old pickup feel new again. We chose the 8-inch Super Duty lift because we were told it would allow fitment of up to 38-inch rubber. We enlisted the expertise of Train's 4x4 of Salinas, California, because owner Mark Train has tons of experience with Donahoe kits and his shop is well known for its quality work. So follow along as we super-size a Super Duty and reveal a few secrets that make Donahoe's kits the top of the line.
6. The rear suspension setup is quite similar to the front on Super Dutys. To disassemble, first the axle was supported, and then the U-bolts were removed. Next, the brake line was replaced with the included longer line. The original shocks were also replaced with the upgraded Bilstein units. Next, the new rear 5-inch leaf packs were installed; a factory 2 1/2-inch block was used to set a level ride height. Once we were happy with the ride height, both the front and rear driveshaft lengths were established. Next, we took a trip over to Pacific Truck Parts of Salinas to have the front shaft lengthened a few inches. It was also necessary to have the rear shaft lengthened. However, the stock Ford unit was a two-piece design. We decided to simplify the rear setup and have Pacific Truck Parts build a completely new one-piece driveshaft to our specs.
If you are going to super-size your pickup, you'll need to purchase a worthy set of tires and wheels to finish the job. We picked a proven combination of 37-inch BFG Bajas mounted on Walker Evans polished aluminum wheels. These wheels are designed to survive in the toughest desert racing environments on the planet; ours were furnished with simulated bead locks to help avoid legality issues. These BFG Baja tires were chosen because they offer a quiet, well-mannered ride on pavement, and have puncture-resistant TriGuard Plus sidewalls and a clean civilized appearance. We had the friendly guys at California Tire and Wheel mount and balance the killer combo for us.
At first we noticed less movement coming from the rear axle during our testdrive. Then after about five or six miles of pavement, we hit a graded gravel road with light washboard. With 36 psi in the rear tires and 40 psi in the fronts, we were blown away by the truck's handling. Gone were the bone-jarring vibrations, stiff jolts, and abrupt moments. Instead, the suspension had a cushy floating feel that instantly made us smile. We found the 37-inch tire diameter didn't adversely affect the Power Stroke's ability to accelerate. The following fill-up proved that the bigger meats caused a slight drop in fuel economy, but nothing drastic. After a week of driving, we asked the owner how he liked the modifications. He told us it made his truck feel new again, and he loved that he could still tow trailers without the rear of the truck sagging.
