Mike "Four X Doctor" Duncan's '86 CJ-7
A passion that was ignited at age 10 with a '53 Jeep M38A-1, which he built and wheeled for 11 years, led Mike Duncan to open his own shop, the FourXDoctor, in Burbank, California, in 1988. Since then, Mike has produced multiple custom vehicles, including a handful to call his own. Among the fleet was a '78 Dodge van he converted to 4WD and equipped with 35-inch tires, and an '81 Jeep Scrambler he still breaks out for Glamis and desert expeditions. His latest creation, however, was built with more than one purpose in mind. Mike's '86 FXD CJ-7 isn't just for fun; it's also his business card.
Mike began building his CJ-7 just as anyone else might; upgrading parts as they'd become deficient and addressing the vehicle's 'wheeling abilities through extensive trail testing. Putting personal and vehicle safety concerns foremost, Mike designed and constructed the six-point rollcage by extending the A-pillars as far rearward as possible. Both sturdy bumpers came next, custom-built by Mike, with the front housing a Warn 8,000-pound winch and the rear supporting a spare tire. Additional rock protection is provided by the FXD rocker guards and Warrior Products diamond-plate rear corners.
As Mike continued to hit the trails in his CJ-7, the stock drivetrain com-ponents were slowly but surely replaced with heavier-duty equipment. A '91 Corvette LT1 TPI 350 made its way under the hood, to which Mike added a custom five-core radiator, dual Optima batteries, a belt-driven air compressor, and an FXD hydro-boost braking system. Fuel is supplied via a custom FXD 24-gallon tank mounted in the stock rear location. An NV4500 five-speed transmission went in next and was mated to the Dana 300 transfer case outfit with a short shaft kit and a twin-stick shifter. Both tranny and T-case are supported by a custom FXD crossmember and skidplate. General Driveshaft in Monrovia, California, supplied front and rear driveshafts to channel power to the rear full-float Dana 60, built by Cone Industries in Templeton, California, and the front shaved, reverse-rotation Dynatrac Pro 60. Both assemblies feature chrome-moly axle tubes, 35-spline axleshafts, 4.56 gears, Detroit Lockers, Wilwood four-piston caliper disc brakes, and FXD differential guards. Using Dynatrac steering knuckles and arms, Mike completed the steering system with an FXD tie rod and drag link and a Lee steering box and hydraulic ram setup.
Through the years, Mike's CJ-7 has seen its share of suspension systems and tire diameters, with each transition ushering in increased articulation and taller, more aggressive rubber. The latest rendition combines coilover shocks, leaf springs, and a 1-inch body lift to clear 37-inch BFGoodrich Krawlers mounted to 17x8-inch Allied Monster bead-lock wheels. The 6-inch Alcan leaf packs hang on custom 9-inch shackles and secure to the axle using an FXD U-bolt flip kit. Rancho RS9000 shocks assist in dampening the rear, and a custom front antisway bar helps to control body roll. In installing the King 12-inch coilover remote reservoir shocks up front, Mike fabricated an engine cage to create more stable upper shock mounts and provide a mounting surface for the shock reservoirs. With the King shocks in place, Mike went about designing the link system, eventually using three links, with the side links attaching to the top of the axle and the center link attaching to the bottom center.