11/1 Update – The NHRA’s Glen Gray has confirmed that the technical department has rescinded the initial engine bore space ruling, issuing the following statement:

“After speaking with several racers and hearing their concerns about the financial impact of the prohibition of the larger bore center engines, we have decided to retract the rule we posted last Tuesday. However, if these engine combinations show a competitive advantage and create an imbalance in parity, we will treat them as a separate combination when making weight, boost, or overdrive adjustments.”

Earlier: The NHRA J&A Service Pro Mod Drag Racing Series brings to a close its 2016 season this weekend at The Strip at Las Vegas Motor Speedway, and the biggest topic in the pit area — other than Rickie Smith almost assuredly wrapping up his third title in four years — will be the rule amendments that the NHRA technical department released earlier this week, which brought about significant changes for some supercharged and turbocharged racers.

Most notably, the NHRA has moved to restrict the boosted engine combinations to a maximum of 4.800-inch bore space blocks and accompanying cylinder heads, leaving the Chrysler Hemi-based engine as the most likely (or perhaps only) choice of competitors moving forward. This, of course, presents some hard decisions for teams with considerable investments in 5-inch bore space engines. With the bore space options simplified down to one such combination, the boost limit has been set at a standard of 38 psi.

In an effort to infuse some new (or old, in actuality) body styles to the class, the NHRA has also instituted a new 50-pound weight break for select “nostalgia” body styles, including the 1937-38 Chevrolet, 1941 Willys, 1953 Studebaker and Corvette, and 1955-57 Chevrolet and Buick bodies.

“The nostalgia bodies help make the class more entertaining and we’re trying to encourage their use. Because they have an aerodynamic disadvantage, we’re giving them the weight break,” Gray explains.

The NHRA has also doubled-down on the prohibition of traction control devices and systems, which is becoming contained within engine management systems in increasing numbers. However, Gray confirms that no ECU’s currently on the market have been blacklisted, but they will, as always, be subject to spot checks to ensure the traction control functionality is inactive.

“ECU’s are permitted if they have traction control, but you can’t use the function, obviously,” Gray says. “The reality is, there are so many ECU’s out there now, and which ones have traction control and which ones don’t is very difficult to know, so we’re going to be checking just to ensure they’re not enabled.”

Photo courtesy NHRA/National Dragster