Another staple of NHRA Pro Stock fell by the wayside today, as the sanctioning body announced late Monday afternoon it was abandoning its original rule of engine manufacturer matching the body style. Starting in 2018, Pro Stock racers will be allowed to run any currently approved engine combination in any currently approved body, regardless of the manufacturer

“The NHRA Technical Department worked very closely with the Pro Stock teams and the vehicle manufacturers in finalizing this rule change,” said NHRA Vice President-Technical Operations Glen Gray. “The cooperation from all of those involved in the process was very encouraging and we look forward to the 2018 Pro Stock season.”

The NHRA revealed their decision in a letter to Pro Stock teams, with the anticipation the move should provide fans with a wider variety of entries in the class, including more Dodge Darts and Ford Mustangs. Since 2013, NHRA's Pro Stock title has been won by Chevrolet Camaros. 

The body styles remain in effect which require a 2009 or later NHRA-accepted 2-door or 4-door coupe or sedan (domestic or foreign) production vehicle. Body, drivetrain, chassis, etc. may not be altered, modified, or relocated, except as outlined in Requirements & Specifications in the Rulebook. Minimum weight at conclusion of run: 2,350 pounds, including driver. Minimum weight on the rear axle at conclusion of run: 1,100 pounds, including driver.

The engine still must be an internal-combustion, reciprocating, naturally aspirated, single camshaft, 90-degree V-8 (i.e., cylinder bank must be at a 45-degree angle from the camshaft/crankshaft centerline, creating a combined 90-degree angle) automotive-type engine with a maximum 500 cid. Aftermarket blocks permitted if designed and cast with OEM approval, and currently accepted by NHRA.

Once an engine is used in a vehicle at an event, that engine cannot be used in another vehicle for the duration of the event. Engine shall consist short block and heads, and will be serialized or otherwise identified at each event.

NHRA also clarified a rule regarding the mandatory fuel-injection units, citing that no part of an injector may protrude above the runner flange into the plenum area.