NHRA 2020 Stock/Super Stock Rule Changes
2020 Rule Changes
SECTION 1A:STOCK, ENGINE:1,PISTONS (Page 5)
(12/4/2019)OEM or NHRA-accepted aftermarket replacements permitted provided such items comply with all requirements set forth in this section. Aftermarket pistons permitted, may be forged, billet or cast and must retain the OEM as-cast or as-forged head configuration. The manufacturer or ID number must remain unaltered and fully visible to determine the correct application.
Intake side of head may be +/-2 degrees from OEM angle between combustion chamber surface to intake flange surface, may not be cut into any part of valve cover fastener holes. Only OEM intake fastener holes are permitted, any additional fastener holes are prohibited. Spacer plates between the intake manifold and cylinder head prohibited. Valve-cover fastener holes must remain unaltered and in their original location.
SECTION 12A:SUPER STOCK, ENGINE:1,CYLINDER HEADS(Page 2) (12/4/2019)
External modifications prohibited except for the following, intake side of head may be +/-2degrees from OEM angle between combustion chamber surface to intake flange surface, may not be cut into any part of valve-cover fastener holes(except for SS/AH).Intake manifold fastener holes must remain unaltered in their original location. Only OEM intake fastener holes are permitted, any additional fastener holes are prohibited. Spacer plates between the intake manifold and cylinder head prohibited. Valve-cover fastener holes must remain unaltered and in their original location
Along with the above info, there are sources telling us that the Index’s for Factory Stock classes will be changed.