Pro Stock is the drag racing class often described as featuring “factory hot rods.”
The nickname reflects Pro Stock’s roots in production-based American performance cars. Unlike Top Fuel dragsters and Funny Cars, whose bodies and chassis are heavily purpose-built, Pro Stock cars retain the recognizable shape and branding of showroom models. Underneath, however, they use highly specialized tube-frame construction, racing suspension, enormous naturally aspirated V8 engines, and carefully developed aerodynamics.
NHRA’s Pro Stock class emerged from Super Stock in 1970. It was created for heads-up competition between heavily modified production-style cars, giving manufacturers and teams a way to showcase muscle-car technology. Early competition featured brands such as Chrysler, Ford, and Chevrolet, and engine rules evolved to balance large- and small-displacement designs.
“Factory” does not mean the cars are sold to ordinary customers or built unchanged on an assembly line. Modern Pro Stock machines are bespoke race cars with carbon-fiber or composite body panels and engines producing well over 1,000 horsepower. They are also different from Funny Cars, which use a flip-top body and nitromethane fuel; Pro Stock cars keep a more conventional silhouette and traditionally run gasoline.