The National Hot Rod Association pro stock class emerged from the production-based super stock in 1970 with a more liberal set of rules and an absence of handicaps. Initially, rules favored big block V8s with Chrysler Hemi engine powered cars winning the world title the first two years. The NHRA attempted to balance the playing field for 1972 and introduced rules allowing for small displacement V8, compact cars carrying favorable weight. On 1 July 1973, the NHRA required pro stock drivers to have competition licenses, just like blown or fuel dragsters and funny cars.
Following a 1973 NHRA rule change to allow records to be set at any national meet, at the 1973 NHRA Winternationals, "Dyno Don" Nicholson set the first official pro stock e.t. record with a 9.33, while Bill Jenkins turned in a record 148.76 mph speed; later at the same event, Nicholson made a 9.01 second/150.50 mph pass, breaking both his and Jenkins' records. Over the 1974 and 1975 seasons, Bob Glidden became the first driver to win two pro stock championships.
In 1982, the NHRA did away with the weight break system and implemented a 2,350 pound minimum weight, 500 cubic inch maximum rule across the board, due to the popularity of the Mountain Motor IHRA pro stock cars. Lee Shepherd won the second of four championships in a row in 1983, the year he also won IHRA's title, making him the first driver ever to do so; he repeated the feat in 1984. In 2016, the NHRA implemented a major overhaul to the engine formula, with hood scoops and double four-barrel carburetors being eliminated and replaced by electronic fuel injection.
The 1986 Commerce, GA, round saw a violent rollover crash suffered by Bob Glidden, which led to the implementation of a "funny-car style" cage around the driver for safety. The introduction of electronic fuel injection in 2016 marked a significant change in the class, with the aim of reflecting modern automotive trends.
NHRA pro stock engines are restricted to a maximum 500 cu in single-camshaft, 90-degree V8, with all raw components available for general public purchase. The engine must be manufactured by the same company as the car body. Modern pro stock engines generally produce around 2.5 hp/in3 and make upwards of 1,500 hp while being naturally aspirated. A complete NHRA pro stock engine can cost upwards of $100,000.
Pro stock clutches utilize multiple discs, which must be serviced after every run to maintain critical tolerances. The most popular transmission was the Lenco planetary design, first used as a four-speed and now as a five-speed. NHRA pro stocks utilize Liberty or G-Force five-speed clutchless manual transmissions.
NHRA pro stock racers use NHRA-approved carbon fiber bodies, with windows manufactured from polycarbonate. Some have noted that the "stock" portion of "pro stock" is not entirely accurate, as little to none of the race cars' bodies have their origins in the respective manufacturers' factories.
Pro stock chassis are welded 4130 chrome-molybdenum alloy steel tubing, with an integrated "funny-car style" cage around the driver. This provides a very rigid and safe driving environment.
Pro stock cars are required to use automotive-type suspension systems, with front suspensions utilizing MacPherson struts with control arms, and rear suspensions using a four-link suspension with coil over shock absorbers connected to a fixed rear axle. Both the front and rear shock absorbers can be adjusted automatically during the run by air circuits that are controlled by an electronic control unit.
The primary means of slowing the cars from their top speeds are the drogue parachutes, with two parachutes required when speeds exceed 200 mph. Four-wheel disc brakes made by aftermarket manufacturers are also used, with carbon fiber rotors.
The factory hot rods may use only racing fuel, which is tested and certified by chemical analysis at events with the sanctioning body's approval. Pro stock fuel systems flow the gasoline at 7.5 US gallons per minute.
The most championships for a driver in pro stock is 10-time champion Bob Glidden. The driver with the most wins in a single season is six-time champion Greg Anderson, who won 15 of 23 events en route to his 2004 championship.
The list of NHRA pro stock champions includes notable drivers such as Ronnie Sox, Mike Fons, and Warren Johnson, with the most recent champion being Erica Enders in 2023, Greg Anderson in 2024 and Dallas Glenn in 2025.
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Corpus source: Wikipedia article "Pro Stock" Sources not consulted: Primary archives, autobiographies, period programmes, specialist publications.
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