The following Stock/Super Stock horsepower changes were released December 7, 2022 produced by the Automatic Horsepower Factoring System (AHFS). This is the scheduled horsepower adjustment for this year. All changes are effective January 1, 2023. It should be noted that these changes include only results produced by the AHFS, and do not include written letters or requests. Those changes are listed separately.

 

         The AHFS is a program based on actual run data compiled from all available runs at NHRA national events. The data-based format provides the ability to calculate average performances for any class and/or engine combination in Stock and Super Stock. The trigger point for the system is 1.00-second or more under the respective index, and must be produced on two different occasions. Engine-combination averages and class averages are then computed and analyzed to determine if a change is warranted. The amount of change is calculated on a stepped percentage basis. Where applicable, adjustments will be effective for the specific car model or body style being evaluated. An automatic adjustment is instituted outside the two-time a year process when a 1.20 and under run is recorded during any NHRA event.

 

         Any comments, thoughts, or requests must be sent in writing to: National Hot Rod Association; Technical Department; attn: AHFS; P.O. Box 5555, Glendora, CA 91740; or e-mail, AHFS@nhra.com or pcvengros@nhra.com

 

 

 

Stock Horsepower Changes

 

Engine                     OEM           NHRA       New

Make           CID      HP             HP            HP            Years Affected

 

Chev            327       275             278           282           67-68

 

Chev            350       180-185      279           283           77-78

 

Chev            350       360             325           330           1970

 

Chev            376       365             365           370           2015

 

Chev            350       590             630           638           17-18

 

Chev            350       600             600           614           19-22

 

Mopar           340       290             304           311           1970

 

Mopar           383       330             294           300           1969

 

Mopar           360       245             310           317           1974

 

Dodge          370       340             399           404           09-10

 

Dodge          392       380             402           408           11-13

 

Mopar           426       365             291           295           1964 

 

Ford             302       140             143           147           1979

 

Ford             302       140             151           153           1974

 

Ford             302       325             325           333           2012

 

Ford             330       450             570           578           2012

 

Ford             330       510             534           547           2012

 

Note: See class guide for specific details

 

 

 

Super Stock Horsepower Changes

 

 

Engine                     OEM           NHRA      

Make           CID      HP             HP            New HP   Years Affected

 

GM               307       140-155      220-223    229           80-88

 

Chev            572       500             500           512           2022

 

Dodge          354       530             537           550           2015

 

Ford             302       560             560           567           2014

 

GM               305       190-230      243           249           88-92 GT

 

GM               305       210-230      258           264           88-92 GT

 

GM               350       225-230      284           288           88-89 GT

 

GM               350       240-245      282           288           90-92 GT

 

GM               350       240-245      293           297           90-92 GT

 

GM               350       250             284           288           90-91 GT

 

Ford             330       435             471           477           2010 FGT

 

Ford             351       275             313           317           1972 GT

 

Pont             428       375             330           335           1968 GT

 

Pont             428       390             335           343           1968 GT

 

Note: See class guide for specific details

 

Class Index Changes

Class            Current Index         Changes                    New Index

SS/VX           11.45                      -.05                          11.40