A School Bus-Sourced 12-Vavle Cummins Powers This Awesome 1959 Chevy Apache

A 12-valve Cummins turbodiesel originally used in a 1995 school bus now powers this 1959 Chevy Apache Fleetside 4×4. Owned and constructed by Eric Barrett of Marceline, Missouri, the truck combines the vintage Chevy body with a modified Ford F-250 chassis, heavy-duty axles, and a five-speed manual transmission. It also incorporates numerous custom-fabricated components and retains its decades-old patina.

From $500 Marketplace Find To Cummins-Powered 4×4

Eric, a welding equipment operator, found the Apache advertised for $500 on Facebook Marketplace. The Kansas listing had been active for quite some time, which initially made him suspicious. However, after speaking with the seller, he determined the offer was legitimate.

“I loaded up the truck and trailer and a couple friends. A speeding ticket and a half a day later we were headed home with it,” Eric recalls.

The Chevy needed extensive work. It had been sitting for years and was missing its engine, transmission, seat, and one hood hinge. The wooden bed floor was rotten, and the interior had deteriorated after the doors were left open to the elements.

Nonetheless, Eric saw potential and transformed it into this incredible machine.

A 12-Valve Cummins With School Bus Roots

Eric sourced the Apache’s 12-valve Cummins turbodiesel through Facebook Marketplace, and it includes an engine-driven air compressor. Its maintenance history apparently worked in Eric’s favor. When he removed the oil pan to reposition it for front axle clearance, he discovered that the engine’s internal components were exceptionally clean. Consequently, he decided to leave the Cummins “pretty stock.” The diesel breathes through an air cleaner sourced from a 1980s Winnebago camper and exhales through a 4-inch downpipe connected to 5-inch-diameter exhaust tubing. Fuel is supplied by a custom 41-gallon tank. Cooling duties are handled by a Ford F-250 radiator and a pair of electric fans. An industrial battery provides electrical power, and Eric fabricated an unusual mounting arrangement using his dad’s old snow chains to secure it. He replaced the Apache’s deteriorated factory electrical system with a Painless Performance wiring kit.

The Cummins’ engine-driven air compressor supplies a rear-mounted air tank that feeds an air horn and a compressed-air system equipped with a 50-foot hose and reel.

NV4500 Five-Speed And NP241DHD Transfer Case

Behind the Cummins is an NV4500 five-speed manual transmission sourced from a wrecked 1999 Dodge 3/4-ton pickup. Eric also acquired the Dodge’s NP241DHD two-speed transfer case for the project.

Modified Ford Chassis And One-Ton Axles

The Apache’s original chassis was replaced with a frame from a 1990 Ford F-250. Eric purchased the donor Ford, removed and sold the components he didn’t need, and recovered his entire purchase price.

Fitting the Chevy body required significant frame modifications. Eric removed 11 inches from the center of the Ford chassis and fabricated an 11-inch frame extension behind the rear axle. He also modified the Apache’s original firewall to accommodate the Cummins, brake booster, and other components.

For the front axle, Eric selected a King Pin Dana 60 sourced from a 1991 Ford F-350 cab-and-chassis truck and its equipped with Mile Market manual locking hubs. The rear axle is a Ford 10.25-inch unit retained from the F-250 donor. Both axles are equipped with 4.10:1 gears.

Eric kept the F-250’s factory leaf-spring suspension, making few changes beyond installing NAPA shocks.

The truck rides on 35×12.50R18 Firestone Destination M/T tires mounted on XD wheels, which Eric also purchased through Facebook Marketplace.

Custom Interior With Family History

The Apache’s interior combines modern equipment with repurposed components and an item connected to Eric’s family.

An OBS Chevy seat replaces the missing original, while Vintage Air air conditioning provides cabin comfort. Other upgrades include an LMC radio with Bluetooth connectivity, aftermarket gauges installed in place of the factory dashboard vents, and a diamond-plate cab floor. Eric also fashioned a headliner from a gunnysack.

The transmission shifter incorporates an axe handle and pistol grip. Meanwhile, the transfer case shifter features his grandfather’s well-worn carpenter’s hammerhead attached to a new handle.

Original Patina And Custom Guardrail Bumpers

Eric retained the Chevy’s weathered exterior, thoroughly scrubbing the body before applying clearcoat to preserve its decades-old patina.

The truck still displays evidence of its past, including a large-caliber bullet hole in the bedside. Eric also incorporated visible welds as decorative elements and fabricated a cool rear bumper step from connecting rods.

Perhaps the most unusual exterior modifications are the custom front and rear bumpers, which Eric constructed from used guardrails. The idea originated during a conversation with a friend.

“Once I got the major parts on and functioning, I didn’t know what I wanted to do for the bumpers. My buddy was over drinking beer and watching me work and said, ‘what about guardrails?’ I immediately said no, then I started to drink a few, then I said, hey, if I can wrap the corners I think that would look OK.”

Eric subsequently visited a business that offered used guardrails and acquired the material needed to fabricate the bumpers.

Additional exterior features include an underbody-mounted air dryer, LED headlights and taillights, and his dad’s old license plate.

More Diesel-Powered Trucks In The Garage

We met Eric and photographed his Cummins-powered Apache at the 2026 4-Wheel Jamboree Fall Nationals in Danville, Indiana. During our conversation, we learned that the Apache isn’t his only diesel-powered project.

His daily driver is a 2001 Ford F-150 SuperCrew equipped with a Mercedes-Benz OM606 3.0-liter inline-six turbodiesel. He also owns a 2000 Chevy 2500 Classic powered by a compound-turbocharged 12-valve Cummins paired with a five-speed manual transmission.

Photos by Ken Brubaker and Eric Barrett