A Daily Driver Retro 12-Valve Swap

Terry Hansen is a dairy farmer in Logan, Utah, with a big family. Needless to say, with a wife and six kids, he needs a lot of room for family outings. Sure, he could have picked up a diesel Excursion or Suburban as the family truckster, but Terry’s passion is buying wrecked vintage trucks and turning them into reliable daily drivers. So buying anything new was out of the question, let alone beyond the budget of a large farm family. He also wanted something that would not only hold the family, but also tow his project vehicles and anything else that needed hauling on the farm.

Terry found a fairly clean, straight and rust-free ’78 Ford F-350 crew cab, complete with the original gas-guzzling 460 big-block. He picked it up for $5,000, and was also able to find a ’90 Cummins 6BT 12-valve to transplant into the Ford.

“I love old Fords, and the Cummins gives me three times the power and fuel economy over the gassers,” says Terry.

Unlike a lot of vintage truck swaps we’ve seen in which the owner simply uses a late-model chassis and running gear and slaps the vintage body over the top of the late-model diesel, Terry opted to do it the hard way, slipping the Cummins 12-valve between the Ford’s frame rails. Luckily, the older F-Series pickups had plenty of room under the hood and wide-enough frame rails to drop the Cummins in place. A 4-inch Skyjacker lift kit provides extra oil pan clearance above the front axle.

Another cool thing about swapping in a 12-valve, according to Terry, is that the wiring for those motors is simple, allowing use of the factory gauges and electrical system without an ECM. The first-gen motor is a VE pump engine that required some tricks and tweaks to fit it in the big Ford. The engine was fitted with a ’97 P- Pump cylinder head for better breathing, and an ’06 Cummins intake manifold. The turbo is also of ’06 Cummins vintage, an HE-351 Holset wastegated to 40 psi. An intercooler, lifted from the same ’06 Dodge donor truck, was fitted out front of the custom top-tank radiator. A ported “tractor” exhaust manifold is used to mount the turbo, while the exhaust is routed out through a custom 4-inch exhaust system. Moonlight Diesel injectors supply additional fuel, while a homemade cold air intake delivers plenty of air to the turbo.

Behind the 12-valve is a ’97 Dodge NV-4500 five-speed manual, which gives the old iron a badly need overdrive gear. A Six State clutch and pressure plate replaces the stock setup. Advance Adaptors of Paso Robles, Calif., was the source for the adaptor that allowed Terry to retain the big Ford’s transfer case. Out back is a Dana 60 rear axle with 3.54 gears, while up front is another Dana 60 high-pinion axle. On a recent dyno pull at Weekend on the Edge, the Ford put down 350 hp and 800 lb/ft of torque, which is respectable for a first-gen powerplant.

The rest of the truck is all 1970s vintage Ford, sporting a grille from a ’76 and a near period-perfect interior with two bench seats fitted with new vinyl from LMC Truck. The interior is still a work in progress, according to Terry, who added his own boost and EGT gauges, along with a tachometer. The rear suspension is set up with overload springs, and a fifth-wheel hitch is mounted in the bed. Elden Dattage Auto Body of Logan, Utah, is credited with the red paint job.

Terry claims the truck is perfect for his needs. It regularly tows 5,000-to-12,000 pounds with ease, and has occasionally pulled much heavier loads than that. “The truck is comfortable to drive and tows well,” adds Terry.

He claims it routinely gets 20-to-22 mpg empty and 16-to-18 mpg when towing. Best of all, it uses the same fuel that most equipment on the farm uses — diesel. UDBG

---