Installing a GM HEI Module

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Calipag

Calipag

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I am trying to clean up the engine harness in our 1970 Dart. It was converted to a Chrysler electronic ignition at some point of its life. Apparently the person who did the conversion only owned yellow wire so every wire is yellow and they did a very poor job at splicing wires and terminating them.
So, I'm looking to clean all that up while we do our V8 swap. I've read about installing the GM HEI Module and had some questions:
1) Does installing the GM Module replace the ballast resistor and ECU?
2) Do you have to replace the stock coil to do this conversion?

Thank you FABO

ign1.JPG


ign2.JPG
 
Calipag said:
I am trying to clean up the engine harness in our 1970 Dart. It was converted to a Chrysler electronic ignition at some point of its life. Apparently the person who did the conversion only owned yellow wire so every wire is yellow and they did a very poor job at splicing wires and terminating them.
So, I'm looking to clean all that up while we do our V8 swap. I've read about installing the GM HEI Module and had some questions:
1) Does installing the GM Module replace the ballast resistor and ECU?
2) Do you have to replace the stock coil to do this conversion?

Thank you FABO
Click to expand...

1. Yes it replaces both.
2. If you use the same coil you still need the ballast resistor to reduce the voltage so it doesn't overheat.

Better off to do the HEI module and a C, D or E core coil, as they are made to use a full 12v.
You'll also get the full benefit of the HEI spark, which allows up to an .050 gap on the plugs.

In a bit here I'll try to post some more info on that for you.

ADDED:
One of the cleanest of the HEI coils I have used is this 94-97 Dodge Ram truck coil.
It runs on a full 12v and does not require a ballast.
It also put out a spark almost 2x what the old canister type does, and is close to half the size of a canister coil.
You can either get the pigtail for it, or do what I did and trim the connector section off and solder direct to the terminals.
These coils work perfectly with the 4 pin or 8 pin HEI modules.
The 4 pin modules like you normally see used are a bit messy in my opinion, and don't have weatherproof connectors like the 8 pin module.

The last picture is my own car using the GM HEI coil and 8 pin module with weatherproof connectors.
I also have the wiring diagrams for all of these combos when you are ready.

94-97RamCoil.jpg


installed.jpg
 
Last edited:
TrailBeast said:
1. Yes it replaces both.
2. If you use the same coil you still need the ballast resistor to reduce the voltage so it doesn't overheat.

Better off to do the HEI module and a C, D or E core coil, as they are made to use a full 12v.
You'll also get the full benefit of the HEI spark, which allows up to an .050 gap on the plugs.

In a bit here I'll try to post some more info on that for you.
Click to expand...
Thank you!
 
TrailBeast said:
2. If you use the same coil you still need the ballast resistor to reduce the voltage so it doesn't overheat.
Click to expand...

Actually TB I ran my old Mopar coil / no resistor, it worked fine I did that just to see........and it did!!!
 
67Dart273 said:
Actually TB I ran my old Mopar coil / no resistor, it worked fine I did that just to see........and it did!!!
Click to expand...

Yea, I have done it too, but it's something I can't recommend to others to do.
You know how that goes.:D
 
TrailBeast said:
Yea, I have done it too, but it's something I can't recommend to others to do.
You know how that goes.:D
Click to expand...
It will for awhile and when the car starts acting like it is vapor locking, it's an over heated coil.
 
69hemibeep said:
It will for awhile and when the car starts acting like it is vapor locking, it's an over heated coil.
Click to expand...

The HEI module has a different dwell time and is not as hard on the coil, but I still wouldn't trust it 100% without a coil that matches the HEI ohm rating.
 
TrailBeast said:
The HEI module has a different dwell time and is not as hard on the coil, but I still wouldn't trust it 100% without a coil that matches the HEI ohm rating.
Click to expand...
I have a CJ5 with a 401 AMC in it and a Davis HEI and love it. It's to bad the top of the distributers are so big for a BB Mopar
 
@TrailBeast I received your email and will get everything together this weekend and install it. Thanks again for all the help. I'll post pics of my before and after.
 
I just went with a new distributor that had the module in it already.
About $50 on EBay...skipwhite or whites speed shop...still available afik.
2 wires, no ballast, no ecu, nada. $8 spare module, 5 minute swap.
Working great so far with at least 30 hours run time on it.

IMG_20180725_175448232.jpg
 
crackedback said:
Haters to the thread in 3...2...1... LOL
Click to expand...
I am guessing this is because some people got together and decided that the Ningbo "ready-to-run" distributor is unreliable because of ## claimed failures (1?), thus nobody is allowed to use it?

I bought one for $45 on ebay (Skip White & others). Looks great for the price, but haven't used yet. Pickup looks better than the Mopars (more like GM w/ multiple sense fingers). If you don't like the module they ship with, you could adapt to a GM 8-pin HEI. Re the later, best to use the GM coil and short cable which connects the 2 for easy plug-n-play (85-95 GM V-8 trucks). If scared of junkyards, buy TrailBeast kit.
 
Have had one of cheap distributors in my 88 D250 that I converted from TBI to carb....Probably been in there over 3 years now...
 
TrailBeast said:
1. Yes it replaces both.
2. If you use the same coil you still need the ballast resistor to reduce the voltage so it doesn't overheat.

Better off to do the HEI module and a C, D or E core coil, as they are made to use a full 12v.
You'll also get the full benefit of the HEI spark, which allows up to an .050 gap on the plugs.

In a bit here I'll try to post some more info on that for you.

ADDED:
One of the cleanest of the HEI coils I have used is this 94-97 Dodge Ram truck coil.
It runs on a full 12v and does not require a ballast.
It also put out a spark almost 2x what the old canister type does, and is close to half the size of a canister coil.
You can either get the pigtail for it, or do what I did and trim the connector section off and solder direct to the terminals.
These coils work perfectly with the 4 pin or 8 pin HEI modules.
The 4 pin modules like you normally see used are a bit messy in my opinion, and don't have weatherproof connectors like the 8 pin module.

The last picture is my own car using the GM HEI coil and 8 pin module with weatherproof connectors.
I also have the wiring diagrams for all of these combos when you are ready.

View attachment 1715237053

View attachment 1715237055
Click to expand...
where did you get your connectors for that
 
amp1956 said:
Thanks and great Idea on wrecking yard because they are quite pricey
Click to expand...
My son and I did as @TrailBeast said and took a trip to the pick a part and picked up the whole set up, coil and module and all the plugs. It turned out really clean, just be careful of the polarity of the 2 wires from the distributor.
 
well I am putting a mild 318 into a 31 model A that's got a big block in it now so weather tight connection will be great I don't have many windows
 
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