We humans love our categories. Our ability to group things based on like traits let our forebears quickly judge what they could eat or what would eat them. It also lets us produce a magazine specifically about hot rods and custom cars.

Naturally, we all have our definitions. To me a hot rod starts as a lightweight, low-cost, mass-produced car that undergoes modifications that make it go faster. J.B. Donaldson’s ’36 Ford roadster fits that category.

But categorization has a wicked stepsister: hasty generalization, the trap that lures us into making snap decisions before learning all of the pertinent information. It was for that reason that I wrote off J.B.’s other car. According to my definition his ’37 Buick is too heavy and his plea that it was one of less than a thousand made didn’t help either.

As he pointed out, though, the car is a different type of hot rod, a factory hot rod. That’s a term that never really sat well with me but he made a pretty good case for it. Hear us out.

Before World War II engine output pretty much matched vehicle size, but starting in 1936 Buick did something novel: it took the biggest engine from its Roadmaster and installed it in the small Special body. The hybrid was good for 100 mph, a lofty speed for all but the most radical purpose-built lakes racers of the day. In fact, Buick dubbed the car Century, a term popular among those racers for the three-figure speed. It was a fast car that people aspired to own in its day.

On the contrary, people didn’t aspire to own newer Fords in the ’30s any more than they aspire to own newer Fords now; they’ve always been ordinary cars. If anything makes ones like J.B.’s roadster desirable it was what people did to them: the people who aspired to own fast and expensive cars like the Buick Century bought those older Fords for cheap and hopped ’em up.

Turn the clock back to the middle of the last century and a kid would’ve built something along the lines of J.B.’s roadster. His crew at J.B. Donaldson Company swapped the engine to one of them hot new overhead-valve jobs, converted the brakes to hydraulic, lowered the suspension, and generally gussied up the car.

Unfortunately, it isn’t 1958 anymore so before anyone could make any changes they—employees Oscar Corrales and brothers Balthazar and Tony Saucedo—had to restore one from a pile of parts that once made up several cars.

The front suspension went back together as Ford designed it, albeit with a dropped Super Bell axle, a Posies Super Slide reversed eye spring, and a ’37 steering box that Don Marks rebuilt. The rear suspension went back together with a Marks-built ’36 axle and a Durant Enterprises monoleaf spring.

To achieve the hydraulic brakes Terry McGavern at Vintage Auto Repair in Phoenix first replaced the stock pedal assembly with one from a ’39. He replaced the front backing plates with self-energizing models from a ’41 Lincoln Zephyr and the rears with non-servo models from a ’39-48 Ford. Instead of using the more common ’40-and-later drums, though, he used ’39 drums, the ones with the 10 1/4-inch bolt pattern that fit ’36-39 wheels; these sport ’36 caps and 6.00- and 7.00-16 Firestones.

Though this one sports a later large-journal 327, small-block Chevrolet engines found their way into early Fords the instant they populated boneyards in the ’50s. Art Morrison’s Machine Shop in Phoenix refreshed it.

A trio of unknown stainless filters scrubs the air for Rochester 2G carburetors on an Edelbrock C-357-B manifold. J.B. again dipped into the old parts pile for a dual-point Mallory distributor, seven-rib Corvette rocker covers, and ram’s horn exhaust manifolds. An early Hurst front mount and a Wilcap engine adapter make the non-ordained union possible. Marks also rebuilt the ’39 gearbox that bolts to that adapter.

You may know J.B. Donaldson Company for its fiberglass versions of the ’35 and ’36 Ford coupe and roadster bodies, but this one is in fact a genuine Ford piece. Corrales and the Saucedo brothers pecked and filed it straight and applied the PPG Concept-series Flame Red.