GM HEI "M4 pin" to female socket distr cap??

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GFlo

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So.... I'm converting to GM HEI as many people have done. But I CANNOT find the right dang coil plug wire! The HEI coil is from a mid to late 90's truck/SUV and it has that odd "M4" or "pin" style terminal. I'm going from that to a traditional MOPAR cap with female socket terminals. It seems this should be a fairly common issue for us MOPAR guys but for the life of me I cannot find the right coil plug wire. All of the make-your-own wires have the normal male terminal to female socket. Can't find that odd M4 / pin style that GM used in the 90's.

Anyone else done this?? Many thank you's.

IMG_7399.JPG
 
I'm not familiar, but it LOOKS like the coil wire, the BARE coil wire simply pushes onto that pin, IE push the pin into the center of the wire?

OMC outboard magneto coils work that way
 
No, there is a specific type of terminal that snaps over it. You can find the original GM wires with that end. I just can't find a plug wire that has that on one end and a female socket on the other. It has to exist, right? Others must've done this.

Terminal styles.png
 
Yes, I had Googled every combination of words I could think of. I did find some lone terminals like this, so if I had to I guess I could get a coil wire kit and buy one of these and make my own. I was just hoping to find a pre-made wire if I could. I think the LS1 coils had this M4/pin as the output type. I found these terminals from Summit which are much cheaper than the one on eBay ($32!). I think they'll work, but wondering what others have done in this situation.

Summit Racing® LS1 Coil Boots SUM-850446
 
Magnecor or Aurora will happily make a coil-to-cap wire to suit this need. They make damn fine spark plug wires, too.
 
Hey Dan! Thanks. I just reached out to Aurora. Hopefully I'll have better luck. Magnecor hasn't responded after multiple attempts.

It seems odd to me, many people have converter mid-90's HEI's to MOPAR's or other cars with socket caps. I'm surprised there isn't an off the shelf solution somewhere.
 
Hey Dan! Thanks. I just reached out to Aurora. Hopefully I'll have better luck. Magnecor hasn't responded after multiple attempts.

It seems odd to me, many people have converter mid-90's HEI's to MOPAR's or other cars with socket caps. I'm surprised there isn't an off the shelf solution somewhere.

Did you even find a solution for this? I had to get an alternator from the junkyard this weekend and while I was there I grabbed this too:
upload_2020-9-28_15-6-20.png


I guess I should have done some more homework first because I've now realized that particular module isn't usable with our distributor pickups and then there's the coil to distributor cap wire problem with that coil.
 
Did you even find a solution for this? I had to get an alternator from the junkyard this weekend and while I was there I grabbed this too:

I guess I should have done some more homework first because I've now realized that particular module isn't usable with our distributor pickups and then there's the coil to distributor cap wire problem with that coil.

Yes, there is a way. As you already know, the HEI module that comes on what you got is looking for a digital signal (square wave). The Mopar distributor puts out analog. No problem, just get the Delco D-1906 HEI module. You can get it on Amazon for about $30. You'll have to grind off one of the aluminum fins on the heat sink you have, but it's not that difficult. Make sure it's flat and use the thermal paste that comes with the HEI module.

As for the spark plug wire, I couldn't get Aurora or Magnecor to get back with me so I made my own, at least to use temporarily. There are several make-your-own plug or coil wire kits out there. I used Moroso #73237 for about $28, but that comes with the traditional male HEI and female socket terminals. Use a female socket on one end of the wire which of course goes to the distributor.

For the coil end, that M4 / pin style was also used on the GM LS coils, so you can get an Accel kit that has two 90 degree boots and the right terminals. About $6 on Amazon:
https://www.amazon.com/gp/product/B06W5324PR/?tag=fabo03-20

Put that on the other end and you're all set.
 
Yeah, I figured out about the module but never tried doing my own ignition wires. I didn't know it was that simple. Thanks for the info!
 
Yes, you just push the wire through the boot, cut the insulation back, fold the wire back over and crimp the terminal over the end. I would still try to find a "professional" made one at some point, but it should work no problem for quite a while.
 
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