This 1966 Ford F-700 Cummins Diesel Build Has Military Tech

You don’t see a Cummins turbodiesel-powered 1966 Ford F-700 flatbed every day—especially one running Oshkosh TAK-4 independent suspension and 53-inch tires. But that’s exactly what showgoers at the 2025 Fall 4-Wheel Jamboree Nationals in Danville, Indiana, saw when they laid eyes on Ethan Porter’s massive, one-of-a-kind vintage truck.

From 361 FE Engine To 12-Valve Cummins

Ethan, owner of Porterbilt Fabrications in Indianapolis, Indiana, never set out to build this 1966 Ford F-700. He originally bought the truck to harvest its flatbed for a 1976 Ford F-500 project—but ended up liking the F-700 more than the F-500.

Out came the F-700’s 361-cubic-inch FE engine, and in went a 12-valve Cummins turbodiesel sourced from a 1996-model-year FedEx box truck. The engine had just 69,000 miles on it and was in solid shape. Before installation, Ethan tore it down to the long block, replaced wear items, and added a “slightly larger turbo” along with an aftermarket three-piece exhaust manifold to replace the problematic OE unit.

NV4500, NP205, And More

Backing the Cummins is a stout NV4500 five-speed manual that Ethan sourced from his buddy’s retired pulling truck. It’s been treated to the fifth-gear fix and a twin-disc clutch. Power flows through a divorced NP205 transfer case that Ethan rebuilt and upgraded with Northwest Fabworks parts. It also packs a transfer case parking brake built with Wilwood components. Finally, Ethan swapped in new T-case output shafts and fabricated adapters for the axles to run 1450-series U-joints. This allows the equal-length driveshafts to be interchangeable.

Oshkosh TAK-4 Units

Ethan originally planned to run AxleTech 4000 axles under the truck—until he spotted a pair of TAK-4 units listed on Gov Planet. The government-surplus assemblies were a fraction of the cost, so he threw in a bid and scored two front-application units. Then he hit the road for California to pick them up. Each bolt-in assembly includes coil-spring suspension, a differential, pneumatic drum brakes, a pneumatic locker, a central tire-inflation system, and 4.63:1 gearing. According to the Oshkosh Defense website, the TAK-4 comes in four versions—Light, Premium Light, Medium, and Heavy—and Ethan’s appear to be the Medium version. The company rates them for an off-road GAWR of up to 23,000 pounds, with 16 inches of independent vertical wheel travel and 15.6 inches of ground clearance on 16R20 tires.

Heavy Frame Modifications

Mounting the TAK-4s to the F-700’s chassis required serious frame surgery. Ethan says that each TAK-4 cradle measures 39 inches wide, while the Ford’s frame comes in at just 34. To make it work, Ethan “shored up” 2.5 inches on each side of the chassis per unit. To fit the front-application TAK-4 out back, he flipped the differential.

The massive 16.00R20 Michelin XZL tires—purchased used—are mounted on 10-lug, two-piece, internal-beadlock, run-flat wheels. Mounting them was no small task. Ethan says, “It took three people 12 hours to mount four tires. It also included a plethora of pry bars, a bead breaker used on semis, and a forklift.”

There’s More

There are many other upgrades that round out the build, including custom tubular crossmembers for the engine, transmission, and transfer case. Dual hand-built 35-gallon aluminum fuel tanks feed the Cummins, while an air compressor and dryer from an 8.3-liter Cummins application handle the truck’s pneumatic needs. PSC Motorsports hydraulic steering keeps the big Ford in check, there’s a custom headache rack, and vintage-style switch panel for the truck’s lighting and lockers.