Automotive technician and New York state resident Brendan Scully says, “I like diesels.” He also says, “I like square-body Fords.” Hence, it makes total sense why he built this incredibly cool, Cummins-powered 1975 Ford F-250 High-Boy 4×4 pickup. The truck was on display in “Diesel Alley” at the 38th Annual Steve Shannon Summer 4-Wheel Jamboree in Bloomsburg, Pennsylvania.

Gas Engine Failure Was The Catalyst For This Build

Brendan says his truck was assembled on May 27, 1975, at Ford’s assembly plant in San Jose, California. This was one of two plants that produced the trucks. Around 2012, the truck made its way to the East Coast, and he purchased it in 2014 from a seller in Richmond, Virginia.

The High-Boy was his daily driver until 2015, when its 390 cubic-inch V8 engine began to give him problems. This turn of events spurred him to swap in a Cummins turbodiesel engine and restore many components of the truck. In fact, he removed the truck’s body, sandblasted the entire chassis, and painted it. Brendan notes that every nut and bolt for the suspension, body, and engine is brand new. He also rewired the truck with a Painless Performance Products wiring harness. The only things he left alone were the truck’s paint, body, and interior.

In With The Cummins Turbodiesel

The Cummins 12-valve turbodiesel was procured from an old Dodge truck Brendan bought from a friend specifically to harvest the block. He rebuilt the engine with a new head and a collection of BD Diesel Performance parts, including a turbocharger, injectors, and a high-power injection pump. Additionally, he installed a Hamilton Cams 188/220 Steel Camshaft. a FASS fuel system, and many other parts. The truck has a trio of new crossmembers, and Brendan also boxed the front of the truck’s frame to adapt a later-model F-series steering box.

Engine exhaust is routed through a 4-inch-diameter exhaust pipe, and cooling is handled by a custom radiator manufactured by Wizard Cooling.

NV4500 Manual Transmission And NP205 Transfer Case

Bolted to the Cummins is an NV4500 five-speed manual transmission, which replaces the stock four-speed manual. Brendan swapped in a hydraulic clutch to replace the factory linkage-style setup. Torque is sent to the rebuilt, divorced, gear-drive NP205 transfer case.

Axles And Suspension

The High-Boy’s front axle is a Hillbilly Wizard–built high-pinion King Pin Dana 60 with Warn manual locking hubs. Out back is the factory Dana 60 axle, and it’s been fitted with disc brakes using a Lugnut 4×4 adapter kit. Both axles have 4.10:1 gears, and the rear differential is a factory limited-slip unit.

Leaf springs comprise the truck’s front and rear suspension. The front springs are custom and provide 6 inches of lift, while the custom rear springs provide 4 inches of lift, supplemented by 2-inch lift blocks. A Skyjacker shock resides at each corner. The lift helps provide room for the 39.5x18R16.5LT Interco Super Swamper TSL Bogger tires on 14-inch-wide Weld wheels. The truck also has a custom crossover steering system from Offroad Design, along with ladder bars and a track bar from Far From Stock.

Inside And Outside

Inside, the 1975 Ford F-250 High-Boy retains the delightful vibe of its era, with a few modern upgrades. For example, it has an A-pillar double-gauge pod that houses turbo boost and EGT gauges. It also features an aftermarket steering wheel and an LMC Truck–sourced head unit with Bluetooth.

The exterior of the truck is in great shape for its age, and Brendan has left it mostly untouched. It exudes the ultra-cool patina of a 50-year-old truck, and that’s like the icing on the cake.