This Cummins 4BT 1948 Willys truck is more than a project. It’s a piece of family history. John Conrad’s grandfather bought it new in the 1950s, and John grew up riding in it, even helping repaint it each spring to keep it looking fresh. Decades later, John took full ownership and pushed the build far beyond a simple restoration. The result is a fully reworked classic with a four-wheel drive conversion and serious diesel power.
Cummins 4BT Turbodiesel Power
At the heart of the build is a Cummins 4BT turbodiesel mounted to the truck’s factory frame. The 4BT is known for durability and torque, making it a perfect match for this Willys. This particular engine was sourced from an old bread truck. John upgraded the ‘plant with a Scheid Diesel injection pump, larger injectors, and ARP head studs, along with custom-fabricated components of his own.
Cooling is handled by a custom radiator paired with a clutch fan sourced from a 1991 Cummins-powered truck. Electrical duties are supported by dual Optima YellowTop batteries, ensuring consistent power for both starting and accessories.
NV4500 Five-Speed Manual Transmission, Dana 300 Transfer Case
Backing the diesel is a rebuilt NV4500 five-speed manual transmission from a 1995 Dodge truck. Power flows into a Dana 300 transfer case sourced from a late-1980s Jeep CJ-7. The case is upgraded with twin-stick shifters and a JB Conversions output shaft featuring a 1350-series yoke.
1-Ton Axles And High-Steer Control
The Willys rides on beefy 1-ton hardware. Up front, a Dana 60 from a first-generation Dodge truck has been narrowed six inches to match the rear track width. It features custom disc brakes using GM 3/4-ton rotors, Jeep J-truck calipers, and custom brackets, along with Warn Premium hubs and the factory limited-slip differential. Steering is handled by a custom high-steer system with PSC hydro assist.
Out back, another Dana 60 from a 1988 Jeep J20 carries a factory limited-slip differential and custom disc brakes. Both axles run 4.10:1 gears, providing a solid balance of crawl and cruise capability.
Custom Leaf Springs, Four Inches Of Lift, 37s
John, who owns JBs 4×4 in Kingman, Indiana, built the suspension himself. The front uses Jeep J-truck leaf springs in a reverse-shackle configuration, while the rear uses 1972 Chevy truck springs with the shackles relocated 2.5 inches to accommodate the longer packs. The setup delivers roughly four inches of lift over stock and is supported by Bilstein 5100 Series shocks at each corner.
The stance is completed with 37×12.50R17 BFGoodrich Mud-Terrain T/A KM3 tires mounted on 9-inch-wide Raceline 935BZ wheels.
Handbuilt Details And Trail-Ready Hardware
Fabrication work extends throughout the truck. John built both bumpers himself. The front bumper houses KC LED lights, dual clevis mounts, and a rebuilt Warn 8274 winch. That winch has its own story, as John pulled it from a wrecked Jeep CJ-5 when he was just 15 years old.
At the rear, the tailgate is a one-off piece. It started as a Jeep Honcho tailgate before being modified with the original Willys inset for a clean, factory-inspired look. Additional exterior upgrades include Truck-Lite LED headlights and paint matched to the color used on 1946 through 1949 Jeep trucks.
Interior Blends Vintage Feel With Modern Function
Inside, the Willys retains its classic character while gaining modern usability. The factory seat frames were refreshed with new padding and leather upholstery. An Alpine head unit feeds four speakers, and a Dakota Digital instrument system provides accurate readouts.
With the switch from a column shift to the NV4500 floor shifter, John installed an Ididit steering column. Other interior upgrades include a custom center console, a Momo steering wheel, and Dakota Digital cruise control, making the truck more comfortable for long-range driving.
A Diesel-Powered Tribute To Family History
John and Hope Conrad’s Willys is not just a restored truck. It’s a blend of family heritage, stout components, modern conveniences, and proven diesel performance.
You might also like
This 1966 Ford F-700 Rocks A 5.9L Cummins Diesel And Oshkosh TAK-4 Military Suspension
This incredible 1966 Ford F-700 has a 12-valve Cummins, Oshkosh TAK-4 independent suspension, and massive 53-inch tires.
