Join Date: Sep 1999
Location: Vancouver, Washingon
Thanked 0 Times in 0 Posts
Re: 72\' GMC to HEI distributor
I've done the Points to HEI conversion a couple times. There are a couple things to keep in mind. GMC used a resistor wire from the ignition switch to "+" coil wire connector of the old points coil. The resistor wire knocks down the battery voltage from the ignition switch to the "+" coil wire connector of the old points coil to about 9 or so volts. I strongly recommend running a new wire from the ignition switch to the "BAT" connector of the HEI connector. If the HEI "BAT" does not get full battery voltage when the ignition switch is in the "ON" & "Start" positions the HEI distributor might not work, or if the HEI does work, it's not going to be working very well.
What I usually do, is find the wire on the ignition switch that is hot when the ignition switch is in the "ON" & "START" positions, and splice a new wire to the HEI "BAT" terminal. I usually get a factory HEI "BAT" wire from a junkyard vehicle, that way my installation looks factory. I then remove the "R" wire from the starter solenoid and wrap the connector with several layers of electrical tape and stuff the tapped connector into the wiring harness making double damn sure that the old "R" connector will never ever touch metal.