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Not So Mellow Yellow LSX454-powered Jeep CJ-7

Posted in Features on September 23, 2016
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Friendly rivalries exist in every family that has a passion for Jeeps, but few reach the level Chet Kokkeler has with his brother-in-law. The two are always trying to out-do the other, be it tow rigs, sand toys, or in this case, CJs built for running Oregon’s massive coastal dune complex.

When brother-in-law started having his CJ customized and a bigger, faster V-8 installed, another unspoken challenge ensued. Chet hates getting beat, so he enlisted the help of his buddies at Dunks Performance in Springfield, Oregon, to strip his already nice 350-powered ’78 CJ-7 to the bare frame and build something that would be hard to beat during the heat of some serious sand battles.

Dunks yanked out the old carbureted 5.7L, replacing it with the vaunted GM Performance LSX454, which is a full race engine making 627 hp at 6,300 rpm. It’s built on the LS small-block but filled with 4340-forged crank and rods, forged 11:1 aluminum pistons, and capped off with a pair of deep-breathing LSX six-bolt cylinder heads.

Then they added a FAST 102mm intake manifold with matching EZ EFI 2.0 system and ignition so there’d never be a fuel delivery issue while taking on the steepest inclines or cruising the street. The fabricators at Jerry’s Muffler just down the street handled the 3-inch exhaust that runs from the Sanderson headers and is masterfully routed along the CJ’s smoothed frame rails.

Stout Powertrain

In all, the combination of EFI and exhaust gives Chet’s yellow dune slayer close to 650 ponies to play with when he lays on the throttle. All that power is channeled through a heavily modified 4L60E that replaced the old Muncie four-speed Chet had used in the past. Tony at Transmission Solutions, another shop near Dunks, made sure the trans could handle up to 700 hp just in case Chet decided to add more power in the future. Having options on the sand is always cool, so Chet went with an Advance Adapter’s Atlas 2 transfer case with a 3:1 ratio for gear splitting. That pushes power through custom driveshafts to a Chevy 3/4-ton Dana 44 front axlehousing narrowed to 63-inches and fit with an ARB Air Locker running 4.10s. The rear housing is a GM 14-bolt running the same gears and locker. Both housings were junkyard finds, acid dipped, sanded smooth, and painted to match the body.

Chassis Works

The fabricators at Dunks spent “hundreds of hours” on the frame, steering, and suspension to get Chet’s CJ so it would handle the challenges on the sand while being smooth as silk out on the open highway. They relied heavily on Sky Manufacturing to help with the frame-off resto and provide the disc brake conversion kit, custom crossover steering components, the three-link front suspension, and the four-link setup in the rear.

During the rear suspension design, the back of the frame was notched to clear the track bar, and Rubicon Express coils with Fox 2.0 shocks were added to control the Dana pickup housing. Then, attention turned to the front where GenRight shock hoops were welded into place to hold the 14-inch King Coil 2.0 coilovers.

Dunk’s fabricated a hydroboost system to push the fluid to the Wilwood discs at each corner where massive 18x12-inch Fuel wheels and 35x12.50 BFGoodrich KM2s put the LSX454’s ponies to the ground. They also fit Currie Antirock sway bars to both ends so there would be no unexpected drama during high-speed runs weaving between steep bowls or making sudden moves at Interstate speeds.

Body Wise

Chet loves power, but he also likes to feel safe and comfortable on the sand because his wife and kids are often passengers. The original steel body is fit with a welded custom cage. A pair of Corbeau LG1 bucket seats are up front, a 40-inch Corbeua Baja bench seat fills the rear, and all are equipped with the requisite passenger safety gear.

He stayed with old-school Auto Meter gauges in the dash, added a Grant steering wheel, and dropped in a fiberglass center console. He also had the floor coated with spray-on bedliner before being painted, nixxing any ideas of carpet.

MetalCloak fenders keep most of the sand out of the interior, while Poison Spyder rock sliders, body armor, and bumpers protect the sheetmetal. The front bumper is home for a Warn Zeon 10-S winch and a Rigid light bar. When serious night driving begins, Chet powers up the 60-inch Rigid combo lightbar across the top of the windshield.

The Oregon landscape contractor has owned his CJ-7 for nearly 16 years, and it’s seen multiple transformations during that time. For now, however, Chet is quite pleased with his bright yellow dune slayer. That’s because down deep he knows his brother-in-law can’t do anything but eat sand and follow his lead—at least for the time being.


Vehicle: ’78 Jeep CJ-7
Engine: GM Performance LSX 454
Transmission: GM 4l60E four-speed automatic
Transfer Case: Advance Adapters Atlas 2
Suspension: Custom 6-inch with King Coils 2.0 and Sky Manufacturing 3-link (front); Rubicon Express rear coils, Sky Manufacturing 4-link and Fox 2.0 Reservoir Shocks (rear); Currie Antirock sway bars
Axles: Narrowed 3/4-ton Chevy Dana 44, ARB Air Locker 4.10 (front); narrowed Chevy 14-bolt, ARB Air Locker 4.10 (rear)
Wheels: 18x12 Fuel
Tires: 35x12.50R18 BFGoodrich Mud-Terrain T/A KO2

This GM Performance LSX454 makes north of 650 hp and is fed by FAST EFI components. The CJ-7 sports a custom aluminum radiator, hydroboost braking, and ARB onboard air system.
Power delivery is handled through a built 4L60E four-speed automatic and an Atlas 2 transfer case with shifters within easy reach of the driver. The floor was coated with spray-on bedliner before being painted.
Rear passengers ride in the comfort of a Corbeau Baja bench seat tucked between the CJs fender wells.
Corbeau LG1 racing buckets and a full rollcage give security to the front occupants when running the Oregon Dunes.
Dunks Performance worked closely with Oregon suspension builder Sky Manufacturing to design the four-link rear suspension under Chet’s CJ-7. It also runs custom driveshafts with 1310 yokes. Foil helps keep fuel from the 15-gallon GenRight tank cool.
The interior of Chet’s ’78 CJ-7 is pretty basic compared to what’s under the hood and beneath the floor.
Ten-inch Rubicon Express coils with Fox 2.0 shocks and Radflow hydraulic bumpstops handle rear suspension duties. Currie Antirock sway bars add stability on the dunes and on the street.
Winches aren’t needed much in the sand, but when push comes to pull, Chet relies on a Warn Zeon 10-S winch to get the job done. Auxiliary lighting comes from a pair of Rigid LED light bars; one under the Poison Spyder front bumper, the other mounted above the windshield.
Dunks Performance worked with Sky Manufacturing to set up a custom three-link suspension and a crossover high-steer on this Dana 44 front axle sourced from a junkyard Chevy 3/4-ton. The housing was cut down to 63 inches and fit with Wilwood disc brakes. Frontend damping and control come from 14-inch King Coil 2.0s and Currie Antirock sway bars.
Traction in sand is a big factor when getting power down, so Chet runs BFGoodrich 35x12.50 Mud Terrains on forged 18x12 Fuel Hostage wheels.
ARB supplies the air to both front and rear lockers. An Optima RedTop battery provides juice, while GenRight shock hoops hold the King Coils steady. The engine compartment is immaculate.
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