I am changing to an Hei Distributor. Can any one give me any pointers on how to install. The old distributor only had one black wire that came from it and was hooked up to the negative terminal on the coil. The new Hei Distributor has three wrires comming from it a red, black, and brown comming from the base not the cap. The new distributor also has the plug in for BAT+ and Ground and Tach on the top comming from the cap.

Wires from the firewall:

All I see is a red wire that used to go to the pos connection on the coil and then the distributor had a black wire that hooked to the neg side of the coil. Where should I hook the red, black and brown wires from the new distributor? I notice the wiper motor uses a red, black, and brown wire set. can I splice into those?

Any help appreciated?

Thanks, Cvette68

 

I installed a HEI in my 70 many years ago. Only wires you will need to connect is a new wire. Your 68 originally had a resister wire from the fuse block to the coil, this resister wire does not supply full 12 volts to the 68's coil. Just wrap electrical tape around the original wire connector and secure it to original harness for safety using the electircal tape. Using a new piece of wire with terminal end on it to connect to the HEI run the other end through the firewall and put a terminal end on it to connect it to the fuse block. Connect it to the center of the fuse block IGN terminal. This connection will give you 12 volts to the HEI when the key is turned on. This was a easy hook up for me.

 

On my mechanical tach drive HEI distributor there are three wires (red, black and yellow) which come from the distributor and are attached via a three way socket connector to three inner terminals in the dizzy cap.

They are the wires from the module to the coil (which is located in the cap).
I then only needed to supply Bat+ lead to the dizzy cap. (outer terminal) This MUST be BAT+ power from the ignition switch (ON) position....
NOT 12V via ballast resistor.

The only other connector terminal in the cap is for electronic tacho, which wouldn't be used in a 68 with mechanical tach drive.....

hope that helps.

 

I just did this on my ’74. Before you remove the old distributor, with the cap on, mark the position of the number one wire on the intake manifold or suitable location (use a ruler from the center). Remove the cap; mark the position of the rotor the same way. Now remove the distributor, noting the location of the rotor when the gears disengage. Reinstall using these marks. Connect the electrical as others have suggested. I installed mine this way, it fired right up. There is a sticky on how to properly set the timing.

Hope this helps,
Robert

 

That's good info for those pulling & then reinstalling same distributor ... but it seems Cvette68 has points dist and changing to a new HEI dist. Also, points dist spark plug wires don't fit HEI cap.

If you have any type New mechanical tach drive dist ... do yourself a favor ... pull the tach crossgear out, clean it & look it over real close ... and liberally lube it with a GOOD moly grease. Also liberally wipe same grease on bottom dist drive gear teeth just before you stab New dist into motor.

 

I changed my points type distributor to a HEI type using the method I noted. Worked well for me. I changed the wires to a 8mm set.

Robert

 

Does the HEI fit under the stock chrome ignition shielding?
Thanks

 

i heard yes and no on the ignition shielding. i think the main issue was with the air filter hitting. there r several threads around here that will let you know more on the subject.

 

The red, black and brown should be in a plug that plugs into the distributer cap. Run a new 12v positive wire from the switch or a terminal that is switched on the fuse block.
I just did my 68 327 and the ing sheilding wont fit over the HEI dist, you have to go to the 75 sheild.
Make sure that the slip on termanils in that plug are snug, I had mine come loose and fall off at night on a dark and desalate road with no phone.

 

did the 8mm plug wires fit your factory wire looms like on a big block?

 

What happens if you run off of original 12V resistor (ballast) wire. On my 74 I installed HEI, checked voltage on original distributor wire... got 12. This power comes on with ignition and my distributor works just fine. I have noticed that I am getting some black deposit building up in the electrode of my #6 cylinder spark plug. It will eventually breach the gap and the plug will stop firing. I take it out, clean it and put it back in and it is fine again back to 8 cyl. not 7. Could it be that my spark isnt powerful enough due to this mistake????

 

You are correct about getting 12 volts when you hook up an HEI to the original ballast wire. The myth keeps circulating that the ballast resistor magically regulates the voltage down. It's a fairy tale!
(My congratulations to OzzyTom for being one of the few who gets this right. )
It is erroneously stated quite often that the HEI needs 12 volts to operate. This is also incorrect. No OEM would put a key part into your engine if it couldn't run just fine down to 6-8 volts. The HEI will work at quite low voltages that are encountered when you accidently leave the lights on, or trying to start the car on a cold day.
You have unwittingly shown how well the HEI will work under difficult conditions by running the system with the ballast resistance in place. The HEI module is usually calibrated to control 5.8 amps into the ignition coil. The inclusion of the ballast resistance has reduced the primary current noticeably, which causes a significant reduction in spark energy to the plugs. It sounds like you may have a fueling issue, but the reduced ignition (energy) capability does not allow the plug to deal with the fouled plug as well.
Run a non resistive wire to the distributor, and see if it will be able to better deal with plug fouling issues.

 

I tried to run my HEI on my 73 with the resistance wire and it screwed up the coil and ingnition module. It is true the wires will privide 12 volts, but that is just on start up. That is why there is a wire that runs from the starter to the dist. The other wire is the resistance wire that opperates when the car is running. Once the starter shuts off, the wire voltage to the dist drops down to 6-8V. I ran a new wire from the IGN terminal on the fuse block to the HEI dist and it ran fine after that. It states in the directions that the system needs the full 12V to work. Sure there will be some times the voltage will be low, but once the car starts it will get a full 12V from the alternator. The short time it runs with low voltage, doesn't hurt it, it is prolonged use that will damage stuff.