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King of the Hammers KOH Rock Buggy Build: Turning a racing 4x4 dream into reality

Warn Industries - King of the Hammers KOH Rock Buggy Build: Turning a racing 4x4 dream into reality

King of the Hammers KOH Rock Buggy Build: Turning a racing 4x4 dream into reality
Written: February 09, 2011
by Travis Pierce

Chris Duffin, an extreme offroad enthusiast and friend to WARN is building a rock buggy with the goal of racing it at the King of the Hammers someday.

Chris bought his first Jeep 4x4 pictured above, a stock 76 CJ 7, 13 years ago when he was in college and it was his daily driver for a few years. Knowing nothing of offroading at the time it only saw dirt roads and the occasional outing with other inexperienced four wheelers. The only upgrade it saw at that time was a Dana 44 front, spring over, and a set of 35's.

After moving to Portland his Jeep became a fulltime offroad vehicle. He added a Currie 9" rear axle, lockers front and rear, 4-1 twin stick transfer case, winch, aftermarket leaf springs, 37's and a few other goodies. He also rebuilt the AMC 401 that it came outfitted with and installed a throttle body injection system on it.

The next phase of his CJ 7's development included a custom built full roll cage as well as an exo cage for the front, extending the wheelbase, leaf packs all hand polished and tapered, etc.

At this point Chris was becoming an experienced offroader taking his Jeep to various locations and terrain in the Northwest. With all this wear and tear, Chris decided to make other modifications, including an axle swap and transfer case replacement. Swapping these components out started a chain reaction selling the drive lines, suspension components, engine, etc, etc which led to his decision to build a ground up custom engineered rock buggy in his home shop/garage. While in the process of planning his buggy build, the first King of the Hammers race with the original 13 members was run. He instantly knew what he would be building the rock buggy for.

His rock buggy has been sitting the last two years due to work, projects, and a 2 year old. But it is now back out of storage and the build is resuming to completion!

Here are some of the specs and link to his Pirate4x4 thread for the build. We will update you as his work progresses. Note that all axle items were designed and manufactured by Chris, less the shafts:
  • Central tire inflation
  • Disc Brakes with Corvette 4 piston calipers
  • Integrated Portal Box Reinforcements
  • Air actuated lockers
  • Perfect ackerman and 45 degree steering (Front & Rear)
  • Custom dual shear steering mounts
  • 18" Sway-a-Way coilovers with full travel on all 4 corners
  • FOA 2" x 4" travel air bumps on 4 corners
  • Currie Sway bars Front and Rear
  • Stak 3 Speed (custom air shifted)
  • TH400 Transmission
  • Chevy 383 with an Edelbrock MPFI (currently still a 350)
  • Separate Setrab & B&M coolers for Engine Oil, Transmission and Power Steering

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