The size of the pulleys is different. A/C pulley is smaller than the non a/c.If you use the wrong combo it will drive the pump at the wrong speed and cause cooling prolems or cavitate the pump. John.


1970 Dodge Charger R/T S.E. 1969 Dodge Dart GTS 440 M-Code 1970 Dodge Charger 500 383/4-speed w/A.C.