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1973 Ford F250 - Original Slim

Posted in Features on March 1, 2010
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Beware the words "just one more." James "Slim" Janssen can tell you why. Not so long ago, the blue F-250 on these pages was glimmering white. During a long weekend in the desert, yours truly was en route from another corner of the Mojave, planning to meet Slim and the rest of the Mojave Mafia for a few hours of photo shoot fun. James and crew had spent most of the afternoon playing in the whoops and turns near the Slash X Café in Stoddard Valley. It was time to give the truck a wipe-down. Before parking, the proud owner cranked the wheel and hit the throttle in the name of "just one more" powerslide. Mid-slide, the outside rear tire blew off its bead, hooking the wheel in terra firma, and sending the truck rubber-side up. Oops.

With a wrinkled cab and no shortage of mangled fiberglass, the repairs seemed daunting. Thanks to Slim's "original" approach to building his truck, it went back together with relative ease. A few months later, the newly-blue Ford was ready for another shoot. When the date arrived, James kept his truck parked pending the photographer's arrival.

That's the story of the photo shoot. Now let's concentrate on the truck's build.

James bought the truck already built, and the original build used bolt-on roll cage and suspension construction. Even though he ended up redoing most of the build, new 'cage and suspension components were still bolted to the frame rather than welded directly on. Bolt-on construction takes more time during the initial build. Instead of welding directly to the frame, landing plates are made to bolt on. This means spending time making the landing plates, and spending time drilling holes in the frame to mount them. Once the plates are bolted in place, rollcage tubing can "land" on the plates. This method also applies to leaf spring hangers, bump stop mounts, and radius arm brackets.

Keith Sato built the front bumper that leads the way. Three Sol Tek HID lights make after-dark desert running an option. Trailer Products was responsible for the dropped center hood and mildly-flared fenders. Five Autofab hood pins keep things secure through the rough.

The bolt-on method has a couple of advantages. First, roll cage sections and suspension components can be unbolted during maintenance and repair. Second, the bolts allow a little bit of "give" between the 'cage and suspension components and the frame. This give helps avoid stress cracks.

The front suspension is classic and simple. Kingpin-style I-beams were slightly extended and then plated in for maximum strength. The rear-steer knuckles were retained, along with the OEM-configuration steering linkage. Tony Sato built James a set of billet front hubs which are lighter and stronger than the '73 pieces. The early '90s flavor comes from the coil bucket-mounted springs and the dual smooth-body Fox 2.0 shocks. A Fox bumpstop on each side updates the performance during hard hits.

A set of Trailer Products bedsides partially camouflage the suspension and structural upgrades behind them. James didn't skimp on the Dzus tabs: nine per side do a great job of keeping the bedsides in place.

Slim's truck is based on a '73 F-250 frame. Instead of the '73 cab, an '85 unit was grafted on. The front fiberglass and grille are '87-to-'91-style and bring on thoughts of the 1990s, a decade still considered by many as desert racing's finest years.

Out back, the bolt-on leaf spring hangers and matching bolt-on shackle brackets are home to a pair of Deaver leaf packs that mount to the top of a Currie-built Ford 9-inch rearend. James wanted to use the same old-school shock setup that the front end had, but found it impossible to achieve the same control using smooth-body shocks. Shock tuning on both ends comes courtesy of Keith Sato, who is Tony's brother and a fellow Mojave Mafia member.

The big 400 breathes through a UNI filter, and is cooled by an all-aluminum PWR radiator. James built the radiator hold-down bracketry. Chrome won't get you home, but it admittedly looks nice on the engine cage's cross-brace. Note the engine bay light: all the better for after-sundown repairs.

Under the dropped-center fiberglass hood, you'll find a mildly-built Ford 400M V-8. A Clay Smith cam, roller rockers, and a 750 cfm double-pumper carburetor help produce about 400 ponies. Behind the 400, a Ford C6 transmission translates crank rpm into driveshaft rpm. The C6 was built by Roy's Transmission in Fullerton, California, who fitted the heavy-duty automatic with a fixed-yoke output. Lucas Oil products lubricate the entire truck.

PhotosView Slideshow
PhotosView Slideshow

Anything else? Definitely. There's no shortage of spare parts on this truck, each with its own slick James-built mount. If the starter dies, James has a spare for that. If the alternator lets loose, James has a spare for that, too. The same goes for the steering tie rods and drive shaft. Tools, along with recovery gear, are also close at hand. "I was on a 7s racing team," James informed. "We ran a Toyota in Best in the Desert and I learned a lot from that experience. When it was time to build my Ford, I already knew what spares I should carry and how I wanted to mount them."

Dual Fox 2.0 smooth body shocks and a bucket-captured coil spring are old-school, but were finely tuned by Keith Sato. Just to the right of the shocks you can see the rod end that replaced the rubber bushing in the I-beam, adding strength.

With the close-ups snapped, it was time for Slim and the F-250 to face off with the desert. James hit the whoops, slammed The Wall, and powerslid Anderson dry lake. Thanks to a set of newly-fitted Champion beadlocks, the tires stayed firmly mounted and the rubber side stayed down.

It was good to see Original Slim and his truck back in action. Rollover repairs often take multiple months, if not years, to complete. Thanks to savvy building techniques and equally-adept friends, the truck was back in blue in a hurry. Even though repairs can be performed, it's always easier to avoid a crash in the first place. What's the best way to do that? Resist the urge to say, "Just one more."

Even the best-tuned smooth-body shocks can't match the tune-ability and position-sensitive control of a bypass shock. A pair of Fox 2.5s control 16 inches of Deaver-sprung rear suspension travel.


'73 Ford F-250
James Janssen / Lake Elsinore, California
Ford 400M with Clay Smith cam, roller rockers, UNI air filter, MSD distributor
750 cfm double-pumper carburetor
PWR radiator, PWR transmission cooler
Ford C-6 with fixed output yoke built by Roy's Transmissions
Front Suspension:
Kingpin I-beams extended and plated, Fox smooth-body shocks, Fox bumpstops, 16 inches of travel
Rear Suspension:
Deaver leaf packs with spring-over mount, Fox 2.5 bypass shocks, Fox bump stops, 16 inches of travel
Rear Axle:
Currie-built Ford 9-inch with Wilwood disc brakes
35-inch BF Goodrich Baja T/As
American Racing Outlaw II fitted with Champion beadlocks
Mastercraft seats, Crow harnesses, Lowrance GPS, Autometer gauges, dash built by James, headliner, seat covers, and door panels by Yvonne Janssen, Kreger Fab tilting steering column, Kenwood race radio

PhotosView Slideshow
PhotosView Slideshow

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