A Rare Rat-Rod: 1965 Ford F-600 with a 5.9L Cummins Swap

• October 21, 2022
• Story By
  Mike McGlothlin

Diesels aren’t exactly new to the rat-rod scene. However, medium duty versions most certainly are. Kudos to Cory Wheat for daring to be different with this one. His frame-swapped ’65 Ford F-600 features 5.9L Cummins power but retains its original, patina’d cab and front clip, all while sporting a one-off, western hauler-style flatbed. An NV4500, Dana 60 and 70 axles, a gooseneck ball in the bed, semi-truck wheels and 37-inch Ridge Grapplers further helped transform this old farm truck into a versatile 4x4 beast that can haul anything Cory needs it to.

A retired grain truck that served time on his late grandfather’s farm, Cory decided to put the F-600 back into service in the summer of 2021. In just over two months’ time, he had the old Ford back on the road, hooked to a tandem axle gooseneck trailer and adding miles to the insanely-low 21,565 number present on the odometer. Right out of the gate, he also earned top honors at the Scheid Diesel Extravaganza show ‘n shine. For a closer look at the running gear under Cory’s chassis-swapped creation, keep scrolling.

From Out To Pasture To Full-On Resurrection

This ’65 F-600 was once used to haul grain for Cory Wheat’s grandpa’s farm. Now, thanks to Cory’s love for breathing new life into old iron, it’s no longer sitting in the weeds. Far from it, the 57-year-old body is mounted to a ’97 Dodge Ram 2500 4x4 frame, and the second-gen axles, suspension and powertrain are along for the ride, too. The skirted, western hauler-style flatbed was homebuilt at Cory’s place of business, Cory Wheat Customs, and is the result of repurposing the original bed (the original bed sides are now the skirting).

The Chassis Swap

Roughly a decade after his grandfather’s passing, Cory decided to make his F-600 roadworthy again. While initial mockup proved the body would mate perfectly over the top of the ’97 Dodge frame rails, the inner fenders had to be cut out to clear the intake and turbo piping for the 5.9L Cummins. Getting the wheels centered in the original fender wells was paramount for Cory as well (i.e. he wanted the finished product to look “right”) and he mounted the body accordingly.

P-pumped 12-Valve

Thanks to no firewall cutting being necessary to make it fit, the 5.9L Cummins looks like it was meant to be under the F-600’s hood. However, the tradeoff in not cutting up the firewall meant things got tight in a hurry in front of the B-series engine. The ’97 Dodge radiator was retained, but the OEM fan clutch assembly couldn’t be, nor could the factory air-to-air intercooler. Electric fans solved the former issue easily enough. The fact that the 12-valve Cummins is a 1997 model year engine and was originally coupled to the NV4500 five-speed means Cory scored the more desirable, 215hp P7100 injection pump. This coveted version of the Bosch P-pump supports both higher rpm and higher horsepower than all others.

Exhaust And Intercooler Work-arounds

Other than disabling the wastegate to provide more boost, the Holset HX35W turbo has gone untouched on the Cummins thus far. However, Cory did have to fabricate his own downpipe-to-hood stack assembly. The custom, 4-inch piece is heat-wrapped and routes to the 6-inch hole in the hood. A black, angle-cut 6-inch exhaust stack provides the finishing touch. Because the factory intercooler couldn’t be utilized due to a lack of real estate in front of the engine, Cory sourced a smaller unit, mounted behind the front bumper, to help keep intake temps and EGT in check.

NV4500 And NP241

If you’re after durability, the combination of a 12-valve Cummins in conjunction with an NV4500 transmission is pretty hard to beat. So when you’ve already got the trusty NV4500 manual transmission mounted in the donor chassis, there is no need to reinvent the wheel. However, the transmission tunnel in the ’65 cab had to be reworked a bit in order to accommodate the NV4500 shifter. The durable, five-speed gearbox has an NP241 transfer case bolted to the back of it.

Modern Suspension And Axles

With the ’97 Dodge donor came a chassis fitted with the factory front coil springs and the upper and lower control arms shown. Along with the suspension came the proven Dana 60 solid front axle up front and the Dana 70 out back. Needless to say, the ride quality is much improved over the ’65 F-600 running gear and arguably better suited for work.

Super Singles And Ridge Grapplers

What sets a work truck off better than semi wheels? These junkyard-sourced 22.5-inch wheels were milled down to 22’s and powder coated black to complete the look of the truck. The spike lug nuts provide the exclamation point. The 22-inch wheels are mated to Nitto Ridge Grappler hybrid terrain tires that measure 37X12.50R22. The 37’s boast an F load range and more specifically a 127Q load index, which means 3,860 pounds of carrying capacity at 80 psi per tire. Cory’s tire choice is fitting, being that the F-600 is often tethered to a trailer.

Mostly Original Interior

In the cab, things are original aside from a set of Rough Country upfitter switches tied in with a multi-light controller mounted up under the hood (which controls the electric fans, headlights and tail lights). The round knob, pull lever shown in the bottom right of the photo above is used as the fuel shut-off for the injection pump. To start the engine, the cable-driven lever is simply pulled toward the driver. To kill fuel supply in order to turn the Cummins off, the lever is pushed back in. The simple fuel shut-off operation fits the truck perfectly, in our opinion, much better than a fuel shut-off solenoid that’s tied in with the ignition would.

It Earns Its Keep

Oh, it gets worked—hard. This is the reason Cory made sure to mount a gooseneck hitch in the flatbed. From transporting new projects home to hauling gravel to daily driving it (yes, it’s his daily driver), Cory’s F-600 more than earns its keep in support of his southern Indiana business.