Diesel Power Straight Axle Swap March, 2009

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Diesel Power	Straight Axle Swap	March, 2009
WHAT KIND OF VEHICLE WERE YOU DRIVNG WHEN you were 18? How would you have liked to have been driving a diesel 4x4 with 10 inches of lift on 40-inch tires? Well, guess what? this '08 GNC Sierra 3500 HD belongs to 18-year-old Patrick Clark of Las Vegas, Nevada-the son of Pat Clark, of Pat Clark Pontiac and GMC, as well as Pat Clark Motorsports. From the very beginning, Patrick wanted to do something different with his new rig. Whether the truck was towing, hauling, of blasting through the dunes, he wanted to have the ultimate four-wheel drive.
     Patrick's stock '08 GMC HD nearly had it all. With the most powerful Duramax engine option available from the factory, arguably the plushest of interiors, and some of the finest creature comforts, the new GMC's are hard to beat, except for one fatal off-road flaw--independent front suspension (IFS). Although this isn't the first lifted Duramax-powered GMC Patrick has driven, it is the first one he's converted to a straight axle frontend. When deciding what to do with his latest truck, he and one of his dad's employees, Ron Reuchalski, came across Off Road Unlimited's website, and quickly realized what need to be done. So, the call was made to Maurice Rozo, owner of Off Road Unlimited in Burbank, California, who was more that happy to install on of his GM straight-axle suspension kits on a willing GMC owner, as well as some other trick off-road accessories.
     Thoroughly built would be an understatement for this truck. Eighteen-year-old Patrick races side-by-sides in the Championship Off Road Racing (CORR) series, so he's no stranger to the off-road world, and wanted a truck as capable off the pavement as it was on it. The straight-axle swap from ORU consisted of a Dynatrac Pro 60 axle, replacing the torsion bars of the factory IFS with a four-link system, 2.5 inch King coilover shocks with reservoirs, King bumpstops, limit straps, and two 2.5 inch King reservoir shocks out back. With 10 inches of total lift, Patrick's HD towers over his previous truck, and '05 3/4-ton with 6 inches of lift and 35-inch tires.
     Any time you build a capable off-road vehicle, tire clearance is an issue that needs to be addressed. Knowing that full suspension travel was a must, Rozo took the truck to a local autobody shop in Burbank. There, all four wheelwells were cut and re-worked to make froom for the 40-inch Mickey Thompson Baja Claws.
     The truck also recieved a host of other off-road-friendly components. Four Hella Rallye 4000 high-intensity discharge (HID) lights were mounted to the front bumper, and four more were added to the Denfeder light rack on top of the cab. While these units only consume 35 watts apiece, they can virtually light up the night, and illuminate much better than customary 100-watt halogen lights. From the rear of the truck, 12-volt power is available, and a Tire Gate replaces the tailgate and carries the spare 40-inch wheel and tire. Last, but not least, a 16,500-pound-capacity Warn winch was mounted behind the rear license plate in case the big GMC ever gets stuck.
     Off-road vehicles need power to blast through the dunes, so the next priority was getting more grunt out of the new LMM engine. The truck was taken to Pacific Performance Engineering, where a Dual Fueles CP3 injection pump system was installed and an Xcelerator programmer turned up the Duramax electronically, while a set of gauges was installed. A 4-inch turbo-back black-coated exhaust from Rolling Big Power was addes as well.
     The interior looks like the ideal cockpit for someone not content with staying on the high way. Four racing seats from Sparco woth four-point harnesses replace the factory captain's chairs up front, as well as the rear bench seats. Seeing a full rollcage is a serious off-road truck is always a welcome sight, and Patrick's truck is no exception. ITI Motorsports of Ontario, California, built the cage fro added Passenger safety.
     When we spoke with Patrick about having his truck built exactly the way he wanted it, he was adamant that not only would it definitely serve its purpose, it woould be put to the test often. Patrick told us that frequent trips to the sand dunes in surrounding states for off-road racing events, as well as dirt bike, ATV, and side-by-side riding are a regular part of his weekly agenda, and that this truck would be expected to haul and tow anything and everything. He then added that the GMC would also frequently. He then added that the GMC would also frequently make its way in and out of the sand and mud whenever he feld the need. With a 65-gallon Transfer Flow fuel tank, we don't think hauling his toys and playing around in the sand or mud several hundred miles away from home will be and issue.

The wheelwells were cut and re-formed by a body shop in Burbank, Californis, in order to accommodate the 40-inch tires. A set of 40x15.50R18 Mickey Thompson Baja Claw tires rides on 18-inch Pro Comp Alloy wheels. A Tire Gate from Wilco Products replaces the tailgate and holds the spare Mickey Thompson Baja Claw

Under the hood, a Dual Fueler CP3 fuel injection pump from Pacific Performance Engineering reduces drive load on the factory CP3 and, in conjunction with a PPE Xcelerator programmer, provides plenty of additional horsepower to get this monster moving.

Hidden behind the rear license plate is a Warn 16.5ti winch. Thanks to Tuff Stuff Products in Stoutland, Missouri, the hinges on the back of the rear license plate can snap to the winch fairlead. Also notice the Class V hitch, which will come in hand when Patrick decides to load up a trailer with any combination of toys.

The four-link straight-axle kit from ORU comes with 2.5 inch diameter King coilover shocks and hydraulic bumpstops, extended brake lines, and limit straps.

The Dynatrac Pro 60 front axle is equipped with an ARB Air Locker, 35-spline 1.5 inch axleshafts, and an Off Road Unlimited finned differential cover. Also notice the hydraulic ram-assisted crossver steering that eliminates the need for a dropped pitman arm, the sway bar for roll control, and the aluminum track bar, which eliminates bumpsteer.

The spotless underbody was laced with trick aftermarket parts. ORU outfitted the stock transfer case with a fixed front dirveshaft yoke, and ARB on-board air compressor mounted along the framerail, and a 65-gallon Transfer Flow fuel tank, which replaces the factory tank. The 4-inch RBP exhaust runs parallel on the left.

Four racing seats with four-point harnesses from Sparco were installed in the interior, and Twisted Stitch outfitted them with seat covers. The four-point rollcage from ITI Motorsports was installed in the back of the cab.

From the rear, you can see the 2.5-inch King reservoir shocks, the factory AAM 11.5-inch rear axle, and a 12-volt power source. ORU also stripped the underbody coating from the frame and painted is glass black.

Eight 35-watt Hella Rallye 4000 Euro Beam high-intensity discharge lights, four and the bumper, and four on the Defender light cage, provide all the visibility one could ever ask for while off-roading at night.