The following Stock/Super Stock horsepower and index changes, produced by the Automatic Horsepower Factoring System (AHFS), were released July 8, 2004. This is the first of the two scheduled changes for 2004. All changes will be in effect beginning Aug. 2, 2004. It should be noted that these changes include only results produced by the AHFS.

The AHFS is a simple program based on actual run data compiled from all available runs at NHRA national events only. The data-based format provides the ability to automatically calculate average performances for any class and/or engine combination in Stock and Super Stock. The trigger point for the system is 1.15-second or more and .25-second or less 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 above the two-time a year process when a 1.40 and under is recorded during any NHRA event.

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

Stock Horsepower Changes
Engine Yr/Make	CID	OEM HP	NHRA HP	HP Adjustment	New HP	Years Affected
Chevy	346	305-310	344	+5	349	1999-02 (Camaro)
Chevy	350	200-270	270	+4	274	1971-72 (Camaro)
Chevy	402	375	400	+5	405	1970 (Nova automatic)
Dodge	340	290	320	+8	328	1970 (Challenger/Barracuda)
Dodge	360	160-190	285	+4	289	1977-80 (Aspen/Volare)
Pontiac	346	305-310	344	+5	349	1999-02 (Firebird)

Super Stock Horsepower Change
Class	Current Index	Change	New Index
SS/AM	9.55	-.10	9.45
SS/AX	9.90	-.05	9.85

Engine Yr/Make	CID	OEM HP	NHRA HP	HP Adjustment	New HP	Years Affected
Chevy	327	250	250	+4	254	1962-64 (GT only)
Chevy	327	250	250	+4	254	1964 (Corvette)
Chevy	350	295-300	310	+4	314	1967-70 (GT only)
Oldsmobile	307	155	223	+3	226	1981-82 (GT only)