I am done with Pertronix. Going to use a dual points distributor now and picked up this Motorcraft dual points distributor today in what appears to be excellent shape. Looks like the code on it says 3D8 in addition to the C5OF12127 which I am told is an early 70s replacement for the HiPo. Only wondering if I should swap out the gear on it given my current engine in the Hertz is a mid to late 80s 302 with a roller cam in it. But it also has roller rockers. Not sure if a roller cam and roller rockers can coexist but definitely has the roller rockers. The gear on a distributor has to match the gear on the camshaft from what I have researched and recently learned. The distributors from that era were mostly cast iron gears and the gear on an 80s Mustang 302 is steel? Therefore change out to a melonized gear?
Just wondering, why did you go back to points? I have never ran Pertronix in my shelby.
A "mid-80's 302", . . . . . well '85 was the first year for "hydraulic-roller camshafts" in the "5.0" ("302"), so be sure that yours is such. Then if it "is" the O.E.M. steel-billet hydraulic-roller camshaft, then yes, you will need to utilized the appropriate "steel" distributor driven gear vs. the older "cast iron" gear as was of previous flat-tappet usage. :)
Scott.
Quote from: hertzz350 on March 16, 2026, 06:26:21 AMJust wondering, why did you go back to points? I have never ran Pertronix in my shelby.
I had my Hertz spontaneously quit on me on two separate occasions, one time being on the Interstate at speed. I would have to pull over and once it cooled down it would start again. I replaced the small module in the Pertronix billet distributor the first time it quit and the problem went away. For a while. A few years later it did it again and once more I replaced the module inside the distributor and it solved the problem for a while. There is a third wire that gets spliced to the ignition switch but after reading about many others having Pertronix problems I am going to revert to older technology. Yes, points need more maintenance but it isn't difficult maintenance. And they are easy to replace. Condensers can go bad but they are plentiful at swap meets and likely eBay too. Plus it looks more stock in the engine bay even though the script should read FoMoCo but those FoMoCo factory installed distributors are hard to find and tend to be rather expensive. I can live with a Motorcraft one.
The offending part.
Quote from: pbf777 on March 16, 2026, 01:10:14 PMA "mid-80's 302", . . . . . well '85 was the first year for "hydraulic-roller camshafts" in the "5.0" ("302"), so be sure that yours is such. Then if it "is" the O.E.M. steel-billet hydraulic-roller camshaft, then yes, you will need to utilized the appropriate "steel" distributor driven gear vs. the older "cast iron" gear as was of previous flat-tappet usage. :)
Scott.
Fairly sure it is an 86 engine that was built for drag racing. But using a composite gear is compatible with everything so I am leaning toward that option than risking premature wear of one of the gears. I will have to change out the Flamethrower coil too so as not to burn up the distributor. Something that runs 9 volts rather than 12.
Converting the original ford ignition to the MSD can be tricky.
The Ford is actually a 6 volt system. The wire that supplies power to the system is connected to the ignition switch which is 12 volts. But it is connected to a pink resistance wire that reduces that voltage. It will be 9 volts cranking but is actually a 6 volt supply running.
The MSD will actually run if connected to that resistance wire but it will cause it to fail within almost a predictable period of time.
IF you want to run the MSD, then you need to run a new 12v wire from the ignition switch.
Without actually seeing your set up, by the failure description of yours, I would expect to find that it runs off the original pink resistance wire.
I prefer the points system. I don't put on enough mileage to make it a burden to run it. Frankly, I think that the Ford dual points gives equal voltage to the plugs as any aftermarket system does.
You are going to need to source a "yellow top" Ford coil to use with your new Ford distributor.
Quote from: shelbydoug on March 17, 2026, 04:51:19 PMConverting the original ford ignition to the MSD can be tricky.
The Ford is actually a 6 volt system. The wire that supplies power to the system is connected to the ignition switch which is 12 volts. But it is connected to a pink resistance wire that reduces that voltage. It will be 9 volts cranking but is actually a 6 volt supply running.
The MSD will actually run if connected to that resistance wire but it will cause it to fail within almost a predictable period of time.
IF you want to run the MSD, then you need to run a new 12v wire from the ignition switch.
Without actually seeing your set up, by the failure description of yours, I would expect to find that it runs off the original pink resistance wire.
I prefer the points system. I don't put on enough mileage to make it a burden to run it. Frankly, I think that the Ford dual points gives equal voltage to the plugs as any aftermarket system does.
You are going to need to source a "yellow top" Ford coil to use with your new Ford distributor.
Points for the win. They worked. They won races as part of a system back in the 60s. You and Uncle Tony agree.
Quote from: deathsled on March 17, 2026, 04:25:56 PMFairly sure it is an 86 engine that was built for drag racing.
This would generally mean we have no idea what the makeup might be; and the original year of production is irrelevant. So what camshaft is in that engine now? ???
QuoteBut using a composite gear is compatible with everything so I am leaning toward that option than risking premature wear of one of the gears.
The advent of the "composite" gears was/is due to the flood of import camshaft cores and that no one knows what'll work with what! And I've been aware of many a scenario where they "didn't" work :o
And believe it or not, in the earlier renditions of the hydraulic-roller from Ford they initially utilized a "bronze" gear; but that didn't work to well in the long-haul, as anybody whom had used them with their mechanical roller cam could have told them! ::)
Scott.
Quote from: shelbydoug on March 17, 2026, 04:51:19 PMI prefer the points system. I don't put on enough mileage to make it a burden to run it. Frankly, I think that the Ford dual points gives equal voltage to the plugs as any aftermarket system does.
Quote from: deathsled on March 17, 2026, 05:01:23 PMPoints for the win. They worked. They won races as part of a system back in the 60s. You and Uncle Tony agree.
That all sounds good, but the simply stated the old '60's "20,000 volt" points system, that as compared to a more modern "40,000 volt" aftermarket electronic system, will provide "less" in overall performance and peak power. . . . . . period! ;)
Scott.
Quote from: pbf777 on March 17, 2026, 05:10:16 PMQuote from: deathsled on March 17, 2026, 04:25:56 PMFairly sure it is an 86 engine that was built for drag racing.
This would generally mean we have no idea what the makeup might be; and the original year of production is irrelevant. So what camshaft is in that engine now? ???
QuoteBut using a composite gear is compatible with everything so I am leaning toward that option than risking premature wear of one of the gears.
The advent of the "composite" gears was/is due to the flood of import camshaft cores and that no one knows what'll work with what! And I've been aware of many a scenario where they "didn't" work :o
And believe it or not, in the earlier renditions of the hydraulic-roller from Ford they initially utilized a "bronze" gear; but that didn't work to well in the long-haul, as anybody whom had used them with their mechanical roller cam could have told them! ::)
Scott.
I've interrogated my father about the camshaft but he's turning 98 in April and doesn't remember anymore. When I pull the Pertronix I can gauge what sort of gear it has and also check for wear and if all seems good, I will go with the same gear which I suspect is steel. I am willing to sacrifice some performance in exchange for more predictability on the road. I'm not doing holeshots with the car and not breaking down while on the move is preferable to top end power.
Swap the gear from your current dist. You know that works with the cam.
There is a specific way to wire the Pertronix so it doesn't fail. Check their website for the diagrams.
Pertronix DO NOT like solid core plug wires.
Coils are 6V (yeah I know some are marked 12V). They get 12V to start from the solenoid. The pink wire in the Mustang harness is a resistor wire that runs the coil on 6V. A lot of Pertronix problems come from using that wire.
A high voltage coil will work on points too - get an epoxy one rather than oil filled. The current condenser market has a lot of bad product floating around - carry a couple spares.
I've got one of the early flat top HP Mallory dual points and a set of NOS points and condenser. I've been reluctant to get rid of it because as you said "They worked. They won races as part of a system back in the 60s."
Quote from: 98SVT - was 06GT on March 17, 2026, 11:26:31 PMThere is a specific way to wire the Pertronix so it doesn't fail. Check their website for the diagrams.
+1 And it's not complicated! :)
We have sold, installed, utilized Pertronix for decades and have found it to be quite reliable, when wired properly. But also, I do like to couple it to an MSD box; . . . . . always looking for more ya'know! ::)
Pertronix is susceptible to damage from voltages in excess of 16V, so ensure that it doesn't experience external charging (battery charger or jumping) voltages much over 15v and also check the voltage regulator function and the alternator's out-put under "full-fielding" ;)
Cause you really shouldn't be having this problem. :-\
Scott.
Quote from: 98SVT - was 06GT on March 17, 2026, 11:26:31 PMThere is a specific way to wire the Pertronix so it doesn't fail.
Yup, and if you do it correctly, it is pretty easy.
Quote from: pbf777 on March 18, 2026, 12:38:45 PM+1 And it's not complicated! :)
Pertronix is susceptible to damage from voltages in excess of 16V, so ensure that it doesn't experience external charging (battery charger or jumping) voltages much over 15v and also check the voltage regulator function and the alternator's out-put under "full-fielding" ;)
Cause you really shouldn't be having this problem. :-\
Scott.
+1. I've used PerTronix on both of my cars for many years. Mostly because I don't like setting points, especially dual points. Not that it is difficult, just annoying. I alway take the 12vdc off the ignition circuit BEFORE the tach and resister wire by plugging in a pre-made single wire with moulded in male and female bullet connectors at either end and then splicing the red wire for the PerTronix into that. That way, there is no damage to the wiring harness and it is easily removable. The Hertz car uses the Ignitor I while I have an Ignitor III in the GT500. And I carry a spare breaker plate in the glove box just in case the thing goes sideways.
How do you guys keep your tach safe? The Tach is running between the ignition and if you have 12v in this you will fry it. I run a MSD Tach Adapter to keep it safe.
Kent,
I don't think that is quite correct. Stock 1966, 1967 and 1968 tachs gets power from the 12 vdc ignition line before the resistor wire (I'm not sure about other years but I'm assuming that they are similar). That is, the tach is wired in series with the 12 vdc ignition lead and the resistor wire, which then goes directly to the coil. When I wire the PerTronix, I run a 12vdc line in parrallel with the resistor wire, only I'm taking power for that line ahead of the resistor wire so the PerTronix unit never sees the 9 vdc or so that goes to the coil. Instead it sees a full 12 vdc. I've got two cars wired this way and I have no problems with either the PerTronix units or the tachs.
Quote from: S7MS427 on March 19, 2026, 11:47:56 AMKent,
I don't think that is quite correct. Stock 1966, 1967 and 1968 tachs gets power from the 12 vdc ignition line before the resistor wire (I'm not sure about other years but I'm assuming that they are similar). That is, the tach is wired in series with the 12 vdc ignition lead and the resistor wire, which then goes directly to the coil. When I wire the PerTronix, I run a 12vdc line in parrallel with the resistor wire, only I'm taking power for that line ahead of the resistor wire so the PerTronix unit never sees the 9 vdc or so that goes to the coil. Instead it sees a full 12 vdc. I've got two cars wired this way and I have no problems with either the PerTronix units or the tachs.
+1 . Roy's description is correct and consequently there is not 12V going to the tach but only going to the Pertronix module. Using the correct wiring that Roy described there is an extra wire with 12v that runs out to Pertronix module .
Buy one of these or make up one of your own:
Pertronix 2001 Ignition Power Relay Kit https://a.co/d/0gTgkg8m
Roy
Quote from: Bob Gaines on March 19, 2026, 12:39:26 PM+1 . Roy's description is correct and consequently there is not 12V going to the tach but only going to the Pertronix module. Using the correct wiring that Roy described there is an extra wire with 12v that runs out to Pertronix module .
Just to be clear, in this setup, the tach receives 12 VDC as it is wired in SERIES with the ignition switch and BEFORE the resistor wire. The coil receives 9 VDC (or so) as it is wired AFTER the resistor wire. The tach receives 12 VDC because it is wired between the switched ingnition wire and the resistor wire. And the PerTronix receives a full 12 VDC as the splice for that is AHEAD of the tach and the resistor wire. It is easy to get lost in this scheme as we are talking about two different voltages: 9 VDC to the coil, 12 VDC to the tach, and 12 VDC to the PerTronix unit. Splicing off of a new wire inserted in the circuit BETWEEN the switched ignition wire (which is 12 VDC) and the tach insures that the proper votages are routed to where they are supposed to go.
I hope this is all clear enough. If I can find my spare slice, I'll post a picture of what it is supposed to look like.
Quote from: S7MS427 on March 19, 2026, 08:09:51 PMQuote from: Bob Gaines on March 19, 2026, 12:39:26 PM+1 . Roy's description is correct and consequently there is not 12V going to the tach but only going to the Pertronix module. Using the correct wiring that Roy described there is an extra wire with 12v that runs out to Pertronix module .
Just to be clear, in this setup, the tach receives 12 VDC as it is wired in SERIES with the ignition switch and BEFORE the resistor wire. The coil receives 9 VDC (or so) as it is wired AFTER the resistor wire. The tach receives 12 VDC because it is wired between the switched ingnition wire and the resistor wire. And the PerTronix receives a full 12 VDC as the splice for that is AHEAD of the tach and the resistor wire. It is easy to get lost in this scheme as we are talking about two different voltages: 9 VDC to the coil, 12 VDC to the tach, and 12 VDC to the PerTronix unit. Splicing off of a new wire inserted in the circuit BETWEEN the switched ignition wire (which is 12 VDC) and the tach insures that the proper votages are routed to where they are supposed to go.
I hope this is all clear enough. If I can find my spare slice, I'll post a picture of what it is supposed to look like.
I misspoke .You are correct about the 12V to the tach.
Thanks for the clarification, Roy and Bob! You're right—I got my wires crossed regarding the voltage.
Voltage (12V) is fine: As you pointed out, the stock '67/'68 tach is wired in series before the resistor wire. This means it has always seen 12V from the ignition switch. The voltage itself isn't what kills it.
The Real Killer (Amperage): The danger comes from current flow. Since the tach is in series, every bit of power going to the coil must pass through the tach's internal transformer/windings.
The "Frying" Scenario: If someone installs a high-performance coil with very low primary resistance and bypasses the pink resistor wire to get a "hotter" spark, the amperage jumping through the tach skyrockets. That's what melts the internals.
The Proper Setup (The Roy Simkins Method):
By running a separate 12V line to the PerTronix unit from a source before the tach (or at the ignition switch), the PerTronix gets the clean 12V signal it needs to "trigger," but the heavy lifting (the coil power) still follows the original path. This keeps the load on the tach within factory specs.
The MSD Confusion:
I mentioned the MSD Tach Adapter because MSD ignition boxes (like the 6AL) use a capacitive discharge system that sends 400V+ to the coil. If you hooked a stock Ford tach to that line, it would be gone in a microsecond. But for a simple PerTronix swap, following Roy's wiring keeps everything safe without an adapter.
To clarify further, even with Roy's wiring, there is a hidden danger when upgrading to a PerTronix III with a low-resistance coil (like the Flame-Thrower III).
The PerTronix III system is designed for very low primary resistance (around 0.32 Ohms). Because the '67/'68 tach is wired in series, the massive increase in amperage required by that high-output coil still has to pass through the delicate internal windings of the tach.
Even if the PerTronix module itself is getting a separate 12V feed, the main 'load' for the coil is still pulling through the tach. If you run a high-output coil, you are pushing much more current through those 55-year-old internals than Ford ever intended. To be 100% safe with a PerTronix III, using a relay (as Roy suggested) is the best way to trigger the coil without melting the tach's transformer.
Horsepower: Switching to PerTronix 1 or 3 on a street engine won't give you a massive HP boost (maybe 1–2 HP). Peak power remains similar if points were well-adjusted.
Driveability: This is where the win is. PerTronix III offers Multi-Spark at low RPM for a smoother idle, better cold starts, and cleaner combustion.
The Dual Points: Dual Points were designed to prevent "point bounce" at high RPM (5,000+). However, modern replacement points often lack the heavy-duty spring tension of original racing parts.
Reliability: Points wear down and the timing drifts. PerTronix offers rock-solid timing that never changes and includes a built-in Rev-Limiter (on the III), which is an engine-saver if you ever miss a shift.
Conclusion: You don't switch to PerTronix for "racing power" alone; you do it for reliability, a smoother idle, and to stop the maintenance headache—all while keeping your original tach safe via a relay.
This is the schematic for the Pertronix 2001 Ignition Power Relay Kit. Hopefully it helps.
Roy
My 69 GT500 is running a Petronix 1 with the 1.6 ohm blaster coil. According to the notes from the previous owner it was installed in the 90's (have to read the notes for the exact year). It's wired directly into the original engine wiring harness. I know the tach is accurate since comparing to a diagnostic test. I've driven at least 1,000 miles last season and a couple thousand since the 90's. With a Pertronix 1 is this something I should worry about?
Also thinking about just converting back to points and not have to worry about it. But is there a good source for quality points these days? All I hear is that they are all Chinesium junk. Trying to make the car as correct as possible and the last thing I want to do is fry the tach.
Quote from: jimhyc on March 20, 2026, 09:23:40 AMMy 69 GT500 is running a Petronix 1 with the 1.6 ohm blaster coil. According to the notes from the previous owner it was installed in the 90's (have to read the notes for the exact year). It's wired directly into the original engine wiring harness. I know the tach is accurate since comparing to a diagnostic test. I've driven at least 1,000 miles last season and a couple thousand since the 90's. With a Pertronix 1 is this something I should worry about?
Also thinking about just converting back to points and not have to worry about it. But is there a good source for quality points these days? All I hear is that they are all Chinesium junk. Trying to make the car as correct as possible and the last thing I want to do is fry the tach.
If you don't see a separate wire out to the Pertronix module for its power and instead getting its power through the factory harness at the coil then a high likelihood of problems at some point.
Quote from: Bob Gaines on March 20, 2026, 09:47:08 AMQuote from: jimhyc on March 20, 2026, 09:23:40 AMMy 69 GT500 is running a Petronix 1 with the 1.6 ohm blaster coil. According to the notes from the previous owner it was installed in the 90's (have to read the notes for the exact year). It's wired directly into the original engine wiring harness. I know the tach is accurate since comparing to a diagnostic test. I've driven at least 1,000 miles last season and a couple thousand since the 90's. With a Pertronix 1 is this something I should worry about?
Also thinking about just converting back to points and not have to worry about it. But is there a good source for quality points these days? All I hear is that they are all Chinesium junk. Trying to make the car as correct as possible and the last thing I want to do is fry the tach.
If you don't see a separate wire out to the Pertronix module for its power and instead getting its power through the factory harness at the coil then a high likelihood of problems at some point.
No separate wire. I'm just going to remove it and go back to stock with points and a yellow top coil. Now to find a good set of points.
I also think about to convert to points so if someone knows reliable dual points just let us know.
Find NOS Ford points, they are worth it
The problem with some aftermarket points is the rubbing block contact area is smaller and dwell loses spec more rapidly. I have Pertronix in My Mach, no issues for 16yrs.
I go on ebay and use Sorenson crosscut FOMX45 points. I have always ran them in my shelby.
I've posted this before but it is everything you need to know with all wires explained. I suggest making up a "Y" connector with bullets to splice into the wiring without any damage (at point 7 on the diagram). Pull apart existing bullet connector and insert there - ignition side of tach.