Upgrade To HEI

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Charlie

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Hello, new guy here. Joined over a month ago checking out the info here.

1974 C10 350/TH350. Decided I want to upgrade to HEI from stock distributor. Have seen a lot of brands available. The 1972 C10 I had previously owned had Accel when I purchased it. Looking at Accel 5048R 65K HEI DISTRIBUTOR. Would like to get opinions on this one and/or different ones that would be good. Engine is stock.


TIA
 

1987 GMC Jimmy

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AC Delco remanufactured Delco-Remy distributor. The ignition control modules in the other ones would scare me. Delco modules are still made in this country, and I trust them more than the six month aftermarket modules.
 

Charlie

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Sorry, used wrong number. Should be HEI000R.
 

gmachinz

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You can also use a Pertronix Ignitor II and keep your oem small dizzy cap. I used to use them in place of points on a lot of 60's-70's stuff with never any issues.
 
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highdesertrange

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I would go with a stock GM HEI. they are highly dependable. highdesertranger
 

75gmck25

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I used a stock replacement HEI I bought from Pace Performance, and its been running fine for about 15 years.

I think it was similar to this one http://paceperformance.com/i-238414...vy-sb-bb-v8-engines-65k-v-coil-black-cap.html.

Also, since HEI became standard in these trucks in 1975, you can buy the 1975 supplement to the 1974 GM service manual, and it has all the HEI documentation. FYI - There is no base 1975 shop manual.

Bruce
 

Charlie

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Boltrunner

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So some may think this is a dumb question... but would my 87 have hei or is it an upgrade that is benificial?
 

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Yes and no to the first question, and there's not really an answer to the second question because you can't change the TBI distributor unless you ditch the TBI. It does have a form of high energy ignition, but it's not HEI in the connotational sense. HEI traditionally refers to the type of mechanical/vacuum advance distributors that came after the point breaker style ignition system. ESC, TBI, and Vortec distributors have high energy outputs because they use the same (ESC) or similar (TBI and Vortec) high energy coils, but they don't utilize weights and springs, vacuum canisters, or simple four pin modules like HEI. Their advance and retard are controlled by ESC modules, and they have more complex ignition modules. I hope that makes sense.
 

theblindchicken

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Yes and no to the first question, and there's not really an answer to the second question because you can't change the TBI distributor unless you ditch the TBI. It does have a form of high energy ignition, but it's not HEI in the connotational sense. HEI traditionally refers to the type of mechanical/vacuum advance distributors that came after the point breaker style ignition system. ESC, TBI, and Vortec distributors have high energy outputs because they use the same (ESC) or similar (TBI and Vortec) high energy coils, but they don't utilize weights and springs, vacuum canisters, or simple four pin modules like HEI. Their advance and retard are controlled by ESC modules, and they have more complex ignition modules. I hope that makes sense.
So theoretically, TBI ignition is an improvement upon HEI due to the computer modules that can adjust the ignition timing based upon the added sensors to the engine?
 

Honky Kong jr

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So theoretically, TBI ignition is an improvement upon HEI due to the computer modules that can adjust the ignition timing based upon the added sensors to the engine?
I say more of a hassle but I'm a locked timing guy lol
 

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So theoretically, TBI ignition is an improvement upon HEI due to the computer modules that can adjust the ignition timing based upon the added sensors to the engine?
That's a tough question, but I would argue a narrow yes for the simple reason that there are fewer moving parts therefore easier to diagnose and repair, and it's more electronically oriented while still being pretty simple so an ECM pinout diagram and a noid light are at most the extra tools you'd need in addition to what you'd already have for HEI diagnostics (at least a multimeter, spark tester, and timing light), and those two extra things are exclusively to get readings related to the ignition control module. The ESC, TBI, and Vortec distributors are simply rotating assemblies so no issues with plates, weights, springs, or the vacuum canister. I would also say that the post-HEI distributors improved in accuracy because of the knock sensor circuit. The 'no' argument could easily hold water from a perspective of mechanical preference. A lot of people like to do a back to the basics build at some point and HEI is perfect for that because delivers spark in a modern fashion with only centrifugal force and vacuum changes dictating it. There's nothing electronic making incremental suggestions or affecting the whole advance curve. From the perspectives of voltage, efficiency, and longevity, I'd say they're all even up until the end of the Vortec incarnation.

Not bashing on HEI at all. It's a really good system that makes point breaker ignition look like Flintstones technology. In my opinion, point breaker ignition only wins in the sense that you can adjust it, and keep it going where HEI either works or it doesn't. I think incorporating some technology into these things and others was a good move, but there's a such thing as too much. Optispark on the Gen II motors sucks big time. It has an indirect mechanical input by optically sensing camshaft position and timing the spark based on that info, and it was totally unreliable in the long run. I don't like the Gen III coil-near-plug system, either. Not because it's unreliable, but because it takes eight coils, multiple sensors, and a complex PCM to do the job that one coil and a simple ECM/knock sensor (at most) can do. I know the second part is my opinion, but I'd say the top part is pretty objective. There are pros and cons, but the TBI distributor does win in terms of simplicity, granted that its simplicity comes at the price of electronic input, and accuracy.
 

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