If your using a points type distributor you can use an internal resister coil and omit the ballast resister but most are going to electronic for better starting and running. Pertronics has an electronic conversion kit that lets you keep you old distributor or many use the GM HEI if your engine is a GM. On an HEI be sure to run a 12g wire from the switch to the dizzy. Many use the factory 16g wire and wonder why modules have a short life. Both the HEI and Pertronics have a proven record over many years.


Evan