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Discussion Starter · #1 ·
I've been monitoring all the talk here on the board about HEI and TFI. I am not here to post another Chevy or Ford fan OPINION. I will only discuss factual information.

If you'll notice, there seems to be a lot of questions by guys trying to put together a TFI upgrade. What parts? What makes? What years? What models? etc. etc. I have to say, GM wins hands down here. Nothing special about the GM HEI parts. They are all common among VARIOUS makes and models of GM vehicles. Parts are EASY to obtain and SIMPLE to install.

The LARGE CAP of the HEI prevents problems such as "cross firing" which can occur when you send thousands of volts of power to the terminals in a smaller cap. This would result in less than a "smooth idle."

The small, compact ignition module contained within the HEI distributor has an incredibly affective way of processing spark control to your plugs based on engine operating conditions and RPMS.

The ONE-WIRE hookup to a switched 12 Volt source eliminates the messy wiring and large ignition control module from under the hood that is usually necessary to operate the stock Duraspark distributors. Not only is this a neater appearance, but also eliminates the less than reliable Motorcraft ignition control module from the circuit.

The GM HEI has been used since the early 70's and continued into the 90's. It has a MORE than proven track record as being a reliable and capable ignition system.

I have looked DEEPLY into the benefits of the TFI and the HEI ignition systems and I have to say, the GM HEI simply has the race won. What more could you ask than for a SIMPLE, ONE-WIRE hookup, compact design that puts out over 45,000 volts of spark to your plugs which give you the benefits of burning less fuel, a larger combustion in your piston chamber for more power, and a far smoother idle than stock? What questions remain???

I have been performing all kinds of moidifications to Jeeps for years. I have sold more GM HEI conversion distributors than I can count. NOT BECAUSE I AM A CHEVY FAN, but because I have formed a FACTUAL analysis of the HEI vs. the TFI and found the HEI to be the best.

After reaching this determination, I began to build the HEI units for Jeep guys (and of course for all of my Jeeps) and I am now selling HEI's for various Jeep engines including the 225 V6, the 258 I6, and now the AMC 290/304/360/390/401 V8 engines. You can see some great photos of these units at my page:

I have so many people come back to me and RANT and RAVE about the HEI's. Many of them have put together their own web pages based on their own installs. Many of these guys claim to be "less than mechanics" and have had NO problems installing their HEI's.

I have seen the DUI units which are a bit expensive, however, they are also a very capable product extremly similar to my GM HEI's for the AMC V8's. In fact, they also use GM components.

The TFI does have some benefits, as well, however it is a bit more complicated system to put together. The GM HEI uses two bushings which tend to wear much less than the Duraspark distributors single bushing design.

I have also seen a lot of name calling and reputation bashing going on here on this forum and I think it's foolish. If you are a Ford fan, GREAT. Go for the TFI if this works for you. If you're a Chevy fan, go for the GM HEI. If you're a Jeep fan and want the best system for your Jeep, go for the GM HEI! (because it simply works best.) PERIOD.

Some people have also mentioned PartsMike and his forum. From what I can see, Mike offers incredibly valuable information to everyone. He does not charge for this service and I would think all Jeep enthusiasts would want to support someone like Mike and his forum, as I am sure everyone can obtain some valuable information from his forum at some point or another.

As for his advertising, I am not sure what "biased" oppinion others are referring to when it comes to Mike's views on HEI vs. TFI, as I have not seen any sponsors on his page that sell either of these items.

I would tend to believe that Mike has also simply found the GM HEI to work best and would obviously voice his oppinion accordingly.

best regards,
Glenn W.


Discussion Starter · #2 ·
Are you trying to convince us to buy an HEI distributor from you? Everybody who has paid attention to the posts on the Motorcraft upgrade has seen that the "facts" that you mentioned are arguable. I would much rather change out the cap, rotor, wires, and coil than remove and replace the entire distributor and then find a source of constant 12V for my HEI! The wiring is already done. I also have a lot more faith in the Motorcraft module than the HEI module. The days of Ford modules failing left and right are long gone. The one in my '89 Ford Bronco had 179,000 miles on it when I sold it and it's still going strong. There is also a lot more cross firing going on in a large cap HEI than the LARGE CAP Ford because of the coil's location. Ever see a LARGE CAP Ford burn through the rotor and have the coil's spark go to ground? HEI is most famous for it. Ever see ozone buildup (the red dust that decreases electrical current transfer) in a LARGE (or small for that matter) CAP Ford? HEI is famous for it.
The reason that you see so many questions about what parts to get is because people don't pay attention or aren't familiar with Ford parts. The parts for the Ford upgrade are just as common and simple to install as the HEI parts. Even moreso when you try to put the HEI on an AMC V8 since you can't buy one in a junkyard. Nothing special about it. BTW, my Duraspark distributors both have two bushings! The Ford upgrade has been around for years, it's just that nobody knew about it. A friend of mine has had a large Ford cap on his since the early 90's.

From what I have seen on this forum, there is a lot of ranting and raving going on about this Ford upgrade. Possibly even more than when everyone discovered HEI for the six-cylinders. There are a lot of guys including it on their web pages also. The best part about it is that is was presented by someone who stands nothing to gain other than the offer of a few beers and recognition that he just helped fellow Jeepers out. You're trying to make a buck off of HEI and I would suspect that this Ford upgrade has threatened that somewhat. Give your "facts" a rest, they don't hold water.

Also, I can tell you why some feel that PM's opinions are biased with an example. There are currently some posts that are asking what one-piece axles to buy. It used to be that PM recommended Superior's one-piece kit. Now his reply is buy from West Coast Differential, one of his sponsors. I'm not saying that WCD doesn't have a good product, but it's funny how his recommendation changed once WCD started sponsoring his forum. I know that the sponsors are necessary to finance the website, but is his opinion now really his own or his need to keep the site up? And PM himself sells HEI kits, so I'm sure that he wants to promote them.

Discussion Starter · #3 ·
One other thing about the TFI upgrade I like is that you can do it in steps as you can afford it, You can get the basics first... base, cap, coil, wires, etc. Then you can get the spring kit, then you can upgrade to the MSD-6A for a bullet proof ignition set-up. The FOMOCO parts are readily available also. The facts are that I can put together as good as or better than HEI setup for less money, and leave myself a sure upgrade path.

· Registered
1,134 Posts
In response to:
"The parts for the Ford upgrade are just as common and simple to install as the HEI parts"

Not sure about your neck of the woods but here in north AL, HEI's are easier to find and are cheaper.
Just my 2 cents! Keep up the arguing though, it makes good reading material! /wwwthreads_images/icons/smile.gif

/wwwthreads_images/icons/cool.gif Big Ed
'88 YJ, 4" susp,3" body,33's,283 Chevy V8,TH350,4.11's,D30,D35c

· Registered
6,784 Posts
CALM DOWN DUDE! No one here said you can't keep your GM HEI!
I can even recommend a few things to make it just as good a choice as the Motorcraft distributor for Jeeps, or any vehicle for that matter...

Everything you just talked about has been covered to death on the posting here.

The 'This and That' parts inventory that is being asked about most of the time is by the I-6 guys.
There is no direct changeover for them, the cap base or adaptor had to be from one year, but the entire rest of the parts can be from one model year.
Ford only used the screw down cap adaptor for two years, so you have to get one for one of those two years.
The rest of the system is from an 84 F-150 with 300 CID I-6, With EEC. for the TFI Coil
83 F-150 with 300 CID I-6 for can coil...

For the V-8 guys, if they want to go TFI, it's 84 F-350 with 460 CID with EEC. That's everything from the distributor cap base to the plug wires.
If they want to stay can coil, it's 83 F-350 with 460 CID without EEC.

Couldn't be much simpler than that...
It's just a distributor and a few wires to change the points vehicles over to Motorcraft, since the distributor and everything else was designed for that engine...

GM HEI was not.

Motorcraft Vs. GM HEI...
1. Runs just as good or better than any GM HEI (that includes the $500 units).
2. Entire upgrade runs between $60 and $100 dollars, depending on the coil you use...
and it's all parts you are going to replace at tune up time anyway.
(Try that with a GM HEI!)
3. No cuing up of the factory wiring harness...
4. PASSES EMISSIONS TESTING!!! Try that with a GM HEI in California or some of the other states...
5. Can be done at your leisure, in your spare time, during your normal tune up time, so it is no extra cost at all.
6. ANY race engine builder will tell you that a GM HEI is a good idea gone horribly wrong. NOT ONE SINGLE TYPE OF RACING VEHICLE USES THEM...
(That should tell you something, even if you are a die hard GM HEI fan.)
7. Stock Motorcraft/ DuraSpark ignitions, particularly with the TFI coil, outperform GM HEI on all counts, from delivering usable spark energy, to controlling stray firings to ground in the caps.
8. Any parts man will tell you that he sells 5 to 10 GM HEI modules to every one DuraSpark unit he sells. (It's because of where Delco chose to locate the module, not the module it's self.)

GM did a lot of things correct, but the HEI wasn't one of them.
If you want to use the GM HEI, by all means do, especially if you upgraded from points.

What goes on inside of ANY distributor cap can only be described as a giant 'SH*T STORM', and GM HEI did little or nothing to correct the problems the HEI had.
They have finally dropped the HEI all together. (Good advice for everyone... If it's 'mother' has given up on it...)

Ford pretty much sat back and watched what GM and Mopar did, and designed out their flaws. As anyone that works on fords knows, they had no problem changing something at the drop of a hat!
Ford has been constantly updating, and has worked out most of the kinks the original ignition had. It's as dependable and as good of output as any of the common factory ignitions.

If you are deficient on knowledge about ignitions, and you are interested in learning, I'll be glad to help you figure out what's important and what's just manufacturers noise, or baseless boasts (or outright lies).

BTW. I'm not affiliated with any factory, and I'm not selling anything here, nor am I trying to keep any sponsors happy.
All I can provide is raw, hard testing data, and some observations and insights gained from doing this for better than 20 years.

(How do you guys like the kinder, gentler me... )

See ya, Aaron.

If Chris Columbus "Discovered" America (with 25 million already here), Can I Go "Discover" Florida?

Discussion Starter · #7 ·
Hey TR!
I must say I like the kinder and gentler version better. I almost always learn something from your posts. I would like to add something, though. Please don't say that NO racing associations use HEI. I live in Iowa where stock car racing is quite popular, and in the hobby stock area almost everybody runs an HEI(everyone that ever wins a race , that is) Granted, this is low tech compared to the exotic machines you've had the pleasure of working on, but these engines also probably more closely resemble those the average Jeeper owns. Keep the positive tone!


Discussion Starter · #8 ·
I have been waiting to hear from other guys that have tried both upgrades, so far I have only heard from one and it sounded like a toss up on which one was better. I did the Duraspark mod about 3 years ago and got good results, but nothing as good as when I put in the HEI. For me, the results speak for them selves.

As for the cost of the HEI: $30 for the dist, $25 for the gear and I already had the wires from the Duraspark mod. The only problem with my wires is that they are blue...(must be a Ford thing).

Right now I have my Ford dist apart on the bench. I'm going through it to make sure everything is in good shape. I plan to drop it back in and do some comparisons...just in case I missed something. But to be honest, unless I do the Nutter bypass, I doubt its going to be any better than the HEI. As for reliability...I have already replaced my Duraspark module once...however, I have never replaced an HEI module.

Of course there are exceptions to every case. And I for one, will not discount any good ideas....and this forum has a lot of them passing through. So...I will sit back and continue to listen to the discussion, and experiment with what I have....and then, hopefully, end up with the optimum system.

"We learn by our mistakes......thats why we are all so damned smart"

John......southern CA
84CJ7, 3"lift, 32"BFG, 4.10's, ARB Locker, Solid Axle's, Durabak

Discussion Starter · #9 ·
i am not sure why this is dragging out the way it has. the duraspark upgrade was brought up as a solution so you did not have to replace a perfectly good ignition system. this led to others asking how to retrofit one in place of their current ignition (ie points). the comparison was also started because someone asked. those of us who answered provided as much fact as possible, as well as our personal experience. i myself (as well as others) did not say "dont buy a hei", we just said there are other options. the hei works OK but is not always the best solution. the reason is that the advance in the hei does not match that of the jeep and can lead to it not passing some areas emission tests.

i would like to know where the facts on the duraspark you claim came from. you may want to recheck them. the duraspark is a simple, reliable, and inexpensive ignition system that has been very well refined through the years. from my own experience as a counterperson, i tested and found many more bad hei modules than ford. i have also seen many more defunct cap and rotors on hei as well. ford did have some problems early on, but gm did as well. the bushing issue in not all true. durasparks often came with two bushings, but i have seen few problems with a single bushing unit. i can go on and on about the goods and bads of both (and the both have plenty) from a technicians point of view, but i wont.

most of us here have nothing to gain by promoting one or the other. myself being of blue oval blood i know the durasprark system in and out. this is not a chevy vs ford thing, it is just another idea to reach an end result.

/wwwthreads_images/icons/cool.gifLET IT SNOW/wwwthreads_images/icons/cool.gif

· Registered
6,784 Posts
I'm mostly a small block fan, chevy or ford, and a few mopars along the way...
In my opinion, as for stock ignition systems go, Motorcraft is the most well designed, and the most powerful for the bucks...
(Opinions are like A$$holes, everybody has one, and they all stink... Take it for what you paid for it...)


*tlendt* wrote,
* I would like to add something, though. Please don't say that NO racing associations use HEI. I live in Iowa where stock car racing is quite popular, and in the hobby stock area almost everybody runs an HEI(everyone that ever wins a race , that is) Granted, this is low tech compared to the exotic machines you've had the pleasure of working on, but these engines also probably more closely resemble those the average Jeeper owns.*

That is true. Most of the "Hobby" stock guys have no budget, are building engines at home, and are using anything they can from stock parts.
Also, some classes restrict them to stock ignitions, so the HEI is the ONLY game in town.

99.99% of Jeepers will never bang into the limitations of either of the stock systems.
I was just trying to get a low buck alternative out there so you could idle smoother, start quicker, get better gas milage, and use some parts that were designed in the 70's and 80's, instead of the 20's and 30's like Jeep used...

My point was you will NEVER see a GM HEI on a NHRA top fuel car, or a NASCAR.

You will see distributors that are using stock Motorcraft triggers, and stock Ford type caps. A bunch of the NASCAR guys are running the Motorcraft TFI style coils, while the top fuel guys need coils you can weld with!
(usually on aftermarket distributors with roller bearings instead of oil bushings, and with MSD cap adaptors and rotors)

I love to watch low buck racing! Nothing like a guy out there throwing dirt on three bald racing tires and a mud grip, hoping the duct tape holds ONE MORE LAP.......!!!
Too bad those days are gone at Indy. I just loved it when the boys from Daytona brought up a stock block push rod car in black and gold, and scared the hell out of the mega buck racers! Go Smokey!

The GM HEI can be made to really hum, but removing the coil from the cap, and using an adaptor, and using a coil that gives better USEABLE spark energy.
There is no shortage of voltage in the stock GM HEI, just ask anybody that got a grip on one when the 'donut' failed or epoxy on the coil housing cracked!!

Voltage isn't the name of the game. 75,000 volts is no good if all it does is weld your advance weights to their pins... or fires the wrong cylinder... or arcs outside the cap!!
That much voltage, or electrical pressure, makes for a thin, white, thready spark of low amperage and short duration.

If you look at the latest factory ignition systems, the coil voltages are around 40,000 , and the amperage and duration are way up...
They can even go to smaller caps when the voltage is dropped to a reasonable level.
If you take a look in a late model GM distributor, you will see shades of the Motorcraft distributor in it... Better insulated distributor shaft, less hardware under the rotor, taller rotor, ribbed cap, vented distributor housing, some vented caps, better center cap contact, terminal, REMOTE COIL, coil specs almost identical to the Motorcraft TFI coil... And the list goes on...

I have a little different view point than most, so I don't consider it ripping off Motorcraft, I consider it the next evolution in ignitions.
Ford will now wait to see what problems surface in the new GM units, and design them out in the next evolution of Motorcraft ignitions... and the cycle repeats again...

I don't look at what is Chevy, or Ford, I look at what is good and bad.
The Motorcraft ignition is better than the GM HEI on all counts except external wiring...
If Motorcraft would have used Weather pack connectors, that wouldn't matter either...

I'm sure the new chevy ignition kicks the butt of the 75 to 86 Motorcraft ignition, as well it should, it's design is 25 years newer.
Lets see what the others do in the next five years or so...
One thing about evolution, I get better parts to play with!!!!

Later folks! Aaron.

If Chris Columbus "Discovered" America (with 25 million already here), Can I Go "Discover" Florida?
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