The Super HEI Kit-which is a smog-legal modification, by the way-allows you to retain an already installed HEI distributor. Depending on the type of module you're running (four-, five-, or seven ...

Originally, the HEI system was fitted with a four-pin module. By 1978, it had a five-pin unit. Seven and eight-pin modules were more a computer-controlled element that came around in the 1980s.

Car Craft tales you through the steps of how to convert a Ford or Chrysler ingition to a GM HEI for a high-performance, more-efficient ignition.