I converted my distributor on my Chevelle from a point type distributor to an HEI distributor. Are there any changes that I need to make in my wiring and connections?
The points distributor used a resistance to lower the voltage to the points in the run position to prevent wear on the points. This was done with either an external ballast resistor or a resistance wire in the ignition circuit depending on the year of the car. For starting purposes, there was a 12 volt override supplied by a separate wire from the “R” terminal on the starter solenoid to the ignition coil. When converting to an HEI there are three issues which must be addressed. The first concerns the resistance in the run circuit. The second concerns the gauge of wire feeding the HEI distributor. The third concerns the starter 12 volt override and the ignition switch. When using HEI, the distributor requires a 12 volt feed. In order to achieve this the ballast resistor or the resistance wire must be removed from the circuit and replaced with a pure 12 gauge feed wire. This feed wire must be 12 gauge from the ignition switch to the bulkhead and then from the bulkhead to the HEI power terminal. This solves the first two concerns. The third situation can be solved in two ways. The original 12 volt override wire from the starter solenoid “R” terminal to the ignition coil must be retained and must be doubled up with the new 12 volt ignition feed before the wires are plugged into the HEI power terminal. The reason this is necessary is that the ignition switch is mutually exclusive in the crank and run positions. This means that there is no power on the “RUN” circuit when the ignition switch is in the “CRANK” mode. Subsequently, without the lead wire from the starter solenoid “R” terminal, the car won’t start. An alternative solution involves changing the ignition switch to one that supplies 12 volts on the “RUN” circuit when the ignition is in “CRANK” mode. With this type of ignition switch, a 12 volt override wire from the starter is not necessary. Subsequently, if your starter had an “R” terminal and you changed the ignition switch as described here, the original 12 volt override wire could be eliminated.