Interesting duraspark delete to gm hei conversion

[Bymguate]

I guess we all have experienced something bad with duraspark or of u havent you will eventually. Heres an easy replacemente for the puke box, cause it literally does, it over heats and the seal on the back of it melts down.
Pros and cons are not gonna be adressed its a personal choice to use duraspark or hei, on my case i have way better experience with hei.

They both work similar, but heres my case, i wanted to control my timming under boost so i installed a boost timming master wich decreases timming advance under boost to desired 1,2,3 or 4 degrees per psi, up to 15 degrees total. Since i installed this my tach died, needed a tach adapter they run around for 60 bucks, my duraspark puked, plus its not a very nice small piece to have in the engine bay if u want to tuck wires to have a clean look.
One thing i liked about it it was the timming decrease on crank, still its not necesary on a low initial timming our engines require. This could work very well on big blocks with very high compression ratio and lots of timming with a crazy tight lobe cam separation, Not on a low comprension 4 banger with wide lobe cam separation.
Well enough said back to the swap.

You do use the stock dusraspark electronic distributor, the are 3 wires violet, orange and black.
Gm hei needs basically 4 wires, dielectric grease and a good ground where it can dispate heat.
It is a 4 pin deignated letters B, C, G, W.
B= COIL POS ACC SWITCH
C= COIL NEG
G= violet from distributor
W= orange form distributor
The black negative from the distributor you can pin it to the gm hei bolt holes in the middle of it.

Make sure to use a nice quality wires, dont attenp to use speaker wire and expect something going bad.
After the swap, my tach started working again, the car runs smoother on high rpms, probably cause i did change the coil to an msd blaster 2 coil.

Well hope this helps someone on the way, and yes i rather have a small spare gm hei in my tool box or ashtray than a big duraspark just in case.

[brianj]

I have had very, very bad luck with replacement GM ignition modules. I went through 3 on smallblock chevys in street rods and 2 in my pickup in a year and a half. The quality of the available parts are quite poor nowadays. I have never lost a Ford ignition module, ever. TFI stuff, sure, Duraspark, no. I actually wound up getting GM ignition modules from junkyards and getting rid of the replacement ones to eliminate the problem. Something to think about if you are going to use one- hunt up a few factory GM modules if you can.

Edit- incidentally, I'm running 20 degrees of initial timing with no problem starting. My boost timing master is still sitting on my workbench. No problems up to 9lbs boost, but I'll have to rethink that if i go higher.

[mcfairmont]

Agreed, I have been a mechanic for over 35 years, and in the 80s, we probably replaced 5 or 6 GM HEI ignition modules for every Ford Duraspark or Chrysler module. We were also replacing HEI coils and distributor caps on a regular basis. I have found the Ford Duraspark ignition system, especially the "blue" boxes to be dead nuts reliable. I guess thats why all the MSD distributors use the Duraspark ignition pickup design. Maybe the 4 cyl. Duraspark is different, but on my V8s, the Duraspark stuff has been bulletproof.

[Bymguate]

Yeah definitelly the gm hei module must be an oem, not those cheap knock offs...
The blue duraspark is the same either 4 6 or 8 cyl.
The design on the distributor yes, but that is not being changed on the this setup.

Ill give it a try, for now 100plus milws no hustle... either way i left everything so the duraspark can be plugged back in with no trouble what so ever.

[Walking-Tall]

The simple and straightforward combination of a '83 Duraspark distributor, factory '86 "TFI" coil, and OEM HEI module on mine has functioned perfectly now for a few thousand miles...

[Bymguate]

The simple and straightforward combination of a '83 Duraspark distributor, factory '86 "TFI" coil, and OEM HEI module on mine has functioned perfectly now for a few thousand miles...

Exactly what i did

[405GT-350]

This is the setup in my mustang that I removed

[grtskydog]

Sorry I'm late to the party here. The HEI/Duraspark combo has always been very reliable in my experience. As stated, stay away from the cheapo parts store modules...but that holds true for the Duraspark replacements as well. Had one leave me stranded once upon a time (GP Sorensen), and it wasn't that old. See my pic below to see how I mounted mine. A trip to the pick-n-pull got me a GM bracket and heat sink (S-10 pickups and Blazers from the mid-90s have em). Then I cut a few holes to accommodate the 4-pin module and the Ford E-coil. The bracket keeps everything together and mounted to the strut tower nicely...where the old module lived. I also cannibalized an HEI dizzy off and old pickup...got the proper wire terminals and a nice OE GM module as a spare to throw in the glove box. If you do this mod, don't forget to give it a good heat sink with the proper compound.





Sorry it's sideways. Isn't that way on my computer...