Have a look at FAR25.109 and the revision, Federal Register Notes 63 FR 8298, No. 32, Feb. 18, 1998, which states:
revise the method for taking into account the time
needed for the pilot to accomplish the procedures for a rejected takeoff; require that takeoff performance be determined for wet runways; and require that rejected takeoff and landing stopping distances be based on worn brakes.
Its my understanding that 737NG was not granted "grandfather" rights and was certified to the new FAA requirements. This should be easy to find in the AFM, have a look at the Accelerate Stop distance charts for the "chart conditions".
This revision was to bring the FARs in line with the JAR requirements.
Cheers
Mutt.