Hei Distributor Install Tips
*Don't forget to disconnect the battery before you start
The HEI distributor has two marked terminals. One is a power source and the other is for a tach signal.
HEI distributors require 12 volts during the ignition ‘crank’ and ‘run’ positions.
Using the optional All-Ignition GM pigtail or your own pigtail, run a 'hot' wire (when in the 'on' position) from the ignition switch to the 'BAT' spade terminal in the distributor cap, the pigtail end will simply clip on to this terminal.
If using an electronic tachometer, use the 'TACH' spade terminal in the cap.
Do not use a ballast resistor or a resistor wire for your ‘hot’ wire. You need full 12 volts to the HEI all the time when the motor is running.
Using a ballast resistor or a resistor wire can burn out the module within the distributor.
Before removing the old distributor, note the position of the rotor and vacuum advance canister. Put a reference mark on the engine or firewall so that the new distributor may be easily installed in the same position.
Loosen and remove the distributor hold-down bolt and clamp. Lift the distributor out. If the engine has been running within the past few minutes, the distributor housing may be hot and coated with hot engine oil. Wrap a shop towel around the distributor to avoid burning your hands and dripping oil.
Lower the new distributor into position. The rotor should be pointing at the same fixed point as the discarded distributor and the vacuum canister aligned with the reference mark.
After the distributor has been lowered into place, you may find that it hasn’t seated firmly against the support boss. This indicates that the lower end of the distributor shaft is not properly aligned with the oil pump drive rod. Do not attempt to force the distributor into position.
Reinstall the hold-down clamp and thread the bolt in just enough to exert a very slight pressure against the distributor. If the distributor is not firmly seated, rotate the engine until it drops down into place.
With the distributor properly seated, tighten the hold-down bolt just enough so that the distributor is held in place, but can still be rotated with a little effort. Again, make sure that the vacuum canister is aligned with the reference mark.