I received this info yesterday from NHRA....
"AMC 66-72 removed optional cam, carb, and intake as they were a dealer option not a factory option."
For verification go to
www.NHRARacer.com and check the Engine Specs and see that the optional carb, intake and camshaft has been removed effective 4/16/13. They are no longer on the engine spec sheet and will no longer be allowed in Stock or S/S.