If I may.
HEI is basically a hotter spark as compared to standard electronic ignition and can be had simply by changing coils to a different design as in the E and C core coils.
The benefits are better cold and hot starts, smoother more fuel efficient idle, and better fuel economy in most cases specifically because of the hotter spark allowing larger plug gaps, and therefore faster igniting and more complete burning of the available fuel.
HEI also has other advantages in the background that a lot of people don't realize.
The background advantages are that if the HEI type ignition modules are also used, you gain a few fairly noteworthy advantages.
Dwell for one, as dwell determines the charge time for the coil to get ready for the next spark and HEI modules control dwell much more efficiently giving the coil the correct time to charge fully.
One way it does this is by having full voltage (no ballast resistor) and therefore allowing the coil to get to full charge quicker.
The older four HEI pin modules you see around work well for what they are, but they do have disadvantages.
Four pin modules are more susceptible to death if they don't have the correct voltage, and also they cannot control engine timing, as well as being more prone to loose connections or atmospheric corrosion unless the person installing it goes to lengths to prevent that exposure.
The newer 7 and 8 pin modules can run in more adverse voltage and weather conditions, and are also capable of controlling engine timing for EFI systems as well as forced induction systems where the ignition timing has to be delayed (retarded) and can do this via commands from fuel delivery computer and sensor systems.
The 8 pin HEI modules are also weatherproof as far as their connections to the coil and modules with near zero atmospheric corrosion causing exposure making them more reliable.
Reliability and availability:
Try walking into a little Mom and Pop parts house and ask for an electronic box or ballast resistor for your car and see what happens.
"We can have one of those for you in 2 days" (or longer) is common.
Same with almost ALL aftermarket ignition systems.
HEI replacement parts are IN STOCK in every little parts house as they are so common in so many newer vehicles.
Buying a specific aftermarket HEI setup like the "All in one" distributors or similar puts you right back into the waiting for not in stock replacement parts, so keep that in mind when considering.
So,
1. Improved reliability
2. Hotter spark
3. More efficient spark control (dwell)
4. Better parts availability
5. Quicker starts
6. Improved fuel burn efficiency.
I build and sell HEI kits that are so easy to install you would probably be surprised, and don't have the drawbacks of proprietary parts that have to be ordered if you need to replace something.
They also use your existing electronic distributor, so replacing or recurving a whole new distributor is not needed.
I would venture an off the top guess that somewhere in the neighborhood of 40 FABO members are running my HEI kit right now, and another 10-15 non member orders have been filled.
In about 3 years 1 module failed and was replaced at zero cost to the owner, and we have telephone and email support for installation if needed.
The kits can be checked into and purchased here.
www.classichei.com
