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Old 02-18-2026, 08:24 PM   #26
Rich69shortfleet
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Re: Lost another HEI module

Just to cover all the bases I replaced the coil with a Pertronix coil. The coil in there was fairly new, don't remember when I replaced it. I don't recall a coil failing so it must have been an upgrade at some point but it was a parts store coil. Hopefully the Pertronix coil and module will now be able to get along as well as any combo could.

EDIT: I remember now, I replaced the coil when I replaced the HEI harness and pickup coil because the wires on the previous coil were rather weak.
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Old 02-18-2026, 10:34 PM   #27
MikeB
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Re: Lost another HEI module

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Originally Posted by Rich69shortfleet View Post
Hopefully the Pertronix coil and module will now be able to get along as well as any combo could.
I hope that combo turns out to be reliable for you!
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1969 Custom/10 LWB -- owned for 37 years. 350/TH350, 3.08 posi, recent AAW wiring harness, 5-lug conversion, 1985 spindles and brakes. Hedman stainless headers. Old Air installation in progress.
1982 Custom Deluxe 10 SWB -- converted from 250-six to roller cam 350 w/ Vortec heads -- sold
1981 C10 Silverado LWB, 305, TH350C -- sold, but wish I still had it!
1969 C10 (not the current one) which I bought in the early 1980s. Paid $1200; sold for $1500 a few years later. Just a hint at the appreciation that was coming.
Retired as a factory automation products salesman.
Worked part-time over the years for an engine builder and a classic car repair shop.
Member here for 26 years! This is the very first car/truck Internet forum I joined. I still used a dial-up modem back then!
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Old 02-20-2026, 10:24 PM   #28
tim_mc
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Re: Lost another HEI module

Most box store HEI modules are OLD tech, including those made in the US. You can get improved spark and way better throttle response with an improved module like one from Performance Distributors/Davis Unified Ignition, made in the USA. I did back-to-back road tests within minutes between with a stock US-made "OE" module and a DUI module. No contest.

https://performancedistributors.com/...-distributors/

Don't just take my word for it - read the reviews at Summit:
https://www.summitracing.com/parts/dui-000222/reviews
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Old 02-21-2026, 02:42 PM   #29
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Re: Lost another HEI module

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Originally Posted by tim_mc View Post
You can get improved spark and way better throttle response with an improved module like one from Performance Distributors/Davis Unified Ignition, made in the USA. I did back-to-back road tests within minutes between with a stock US-made "OE" module and a DUI module. No contest.
Interesting. What differences did you notice? Was the same coil used with both modules? And what did you use for heat sink compound?

I'm certainly not pointing a finger at you, but sometimes people get bit by confirmation bias. But if it's as big a difference as you say, I may buy one!

Thanks.
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1969 Custom/10 LWB -- owned for 37 years. 350/TH350, 3.08 posi, recent AAW wiring harness, 5-lug conversion, 1985 spindles and brakes. Hedman stainless headers. Old Air installation in progress.
1982 Custom Deluxe 10 SWB -- converted from 250-six to roller cam 350 w/ Vortec heads -- sold
1981 C10 Silverado LWB, 305, TH350C -- sold, but wish I still had it!
1969 C10 (not the current one) which I bought in the early 1980s. Paid $1200; sold for $1500 a few years later. Just a hint at the appreciation that was coming.
Retired as a factory automation products salesman.
Worked part-time over the years for an engine builder and a classic car repair shop.
Member here for 26 years! This is the very first car/truck Internet forum I joined. I still used a dial-up modem back then!

Last edited by MikeB; 02-21-2026 at 04:05 PM.
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Old 02-21-2026, 04:22 PM   #30
tim_mc
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Re: Lost another HEI module

I upgraded to DUI coil and module on the same day in June '21 and used the DUI coil when testing both modules. I used the heat sink compound that came with them. The DUI HEI module improved starting, idle and throttle response/acceleration. After driving with the DUI module, I was so surprised that I pulled the truck back into the garage & swapped back to the OEM module, which ran poor by comparison. I then switched it back to DUI and confirmed that it wasn't my imagination. It's a great low-buck upgrade for everyday driving. I later regapped my plugs to take advantage of the hotter spark.

I gave a DUI module to my brother for his '69 396 SS Chevelle and we noticed an improvement in its performance too. Even just idling and blipping the throttle we could tell it was better. He was doubtful before we installed the new module, but he's a believer now.

OEM High Energy Ignition dwell specs and component technology are from the early '70s with ACDelco D1906 modules used in everything from 4-cyl Chevettes to big block Corvettes. DUI, Pertronix, etc. applied updated design & technology to increase the electronic dwell within the module for a hotter and longer duration spark. It's a good example of a track/performance development that can benefit everyday driving through improved combustion efficiency.

Anyhoo, here's a link to PerTronix module info, which offers a similar description of how it's better over stock: https://pertronixbrands.com/products...m-4-pin-module
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Old 02-21-2026, 05:00 PM   #31
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Re: Lost another HEI module

Thanks, Tim. For around $70, I think it's worth an experiment. I've spent as much or more on stuff that's still in boxes! Heck, even DUI's complete distributor isn't outrageously expensive.

I don't care about high RPM performance, but do care about starting ease, throttle response, and all-around performance.

Still can't believe how long my MSD module has lasted. I don't remember if it was intended to work like a stock one, or if it had a little more current and dwell time.
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1969 Custom/10 LWB -- owned for 37 years. 350/TH350, 3.08 posi, recent AAW wiring harness, 5-lug conversion, 1985 spindles and brakes. Hedman stainless headers. Old Air installation in progress.
1982 Custom Deluxe 10 SWB -- converted from 250-six to roller cam 350 w/ Vortec heads -- sold
1981 C10 Silverado LWB, 305, TH350C -- sold, but wish I still had it!
1969 C10 (not the current one) which I bought in the early 1980s. Paid $1200; sold for $1500 a few years later. Just a hint at the appreciation that was coming.
Retired as a factory automation products salesman.
Worked part-time over the years for an engine builder and a classic car repair shop.
Member here for 26 years! This is the very first car/truck Internet forum I joined. I still used a dial-up modem back then!
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Old 02-21-2026, 06:14 PM   #32
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Re: Lost another HEI module

You bet Mike. I rarely crack 2500 RPM, but love the starting, idle and acceleration improvements. I don't know about MSD's module, and Holley's website doesn't mention anything about Street Fire P/N 5596 being better than stock. I found this at Summit (priced at $60.65):
MSD Street Fire Ignition Controller Modules

MSD offers budget pricing and big performance with their Street Fire ignition controller modules. Their modules improve performance with multiple spark, more spark, and ensured combustion for a cleaner burn to set the streets on fire. MSD ignition modules will show you the benefits of greater throttle response, smoother idle, and full power output at high rpm. Fire your engine for less with MSD Street Fire ignition controller modules.

If you get a DUI module (or similar), I'd definitely be interested to know how it works for you.
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Old 02-21-2026, 06:33 PM   #33
Rich69shortfleet
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Re: Lost another HEI module

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I hope that combo turns out to be reliable for you!
Me too.

The truck has always started at barely a touch of the key, idles great and runs and accelerates great. I doubt the Pertronix can improve on that (at least the starting part) but we will see. Too snowy to drive the truck right now. All I did after I installed the coil was to start it to make sure it was working as installed.
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Old 02-21-2026, 06:42 PM   #34
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Re: Lost another HEI module

Had a msd billet hei in my 73 for years outlived 2 sbc. Had a spare module that I had in a standard hei and never needed it.
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Old 02-21-2026, 10:19 PM   #35
MikeB
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Re: Lost another HEI module

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Had a msd billet hei in my 73 for years outlived 2 sbc. Had a spare module that I had in a standard hei and never needed it.
That's been my experience over the years. In addition to the 20-yr old module I mentioned, I also ran one of their digital distributors (the E-curve) for a few years (back when it cost only $300-something). And friends have used the MSD 6A and 6AL boxes with no issues. But again, those were all probably made in the USA. Then enter Holley's parent company and their buyout of MSD.
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1969 Custom/10 LWB -- owned for 37 years. 350/TH350, 3.08 posi, recent AAW wiring harness, 5-lug conversion, 1985 spindles and brakes. Hedman stainless headers. Old Air installation in progress.
1982 Custom Deluxe 10 SWB -- converted from 250-six to roller cam 350 w/ Vortec heads -- sold
1981 C10 Silverado LWB, 305, TH350C -- sold, but wish I still had it!
1969 C10 (not the current one) which I bought in the early 1980s. Paid $1200; sold for $1500 a few years later. Just a hint at the appreciation that was coming.
Retired as a factory automation products salesman.
Worked part-time over the years for an engine builder and a classic car repair shop.
Member here for 26 years! This is the very first car/truck Internet forum I joined. I still used a dial-up modem back then!
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Old 02-22-2026, 02:50 AM   #36
KQQL IT
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Re: Lost another HEI module

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Originally Posted by MikeB View Post
That's been my experience over the years. In addition to the 20-yr old module I mentioned, I also ran one of their digital distributors (the E-curve) for a few years (back when it cost only $300-something). And friends have used the MSD 6A and 6AL boxes with no issues. But again, those were all probably made in the USA. Then enter Holley's parent company and their buyout of MSD.
Im beginning to learn with a msd 6014 ls swap box.
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