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Finding the correct OEM 1970, 302 Distributor

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wilcom

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Thank you all for your replies. I think I will proceed with the dura spark setup. ( For the record, I bought the Bronco in CA but moved to Nevada years ago. The vacuum I believed was single type due to only one vac port but maybe dual diaphragm.)
I will try and find a Duraspark I Dist and Red tab module some place in new or like new websites.
Has any one used the Cordone? or suggestions on where to find OEM Duraspark Dist?
 

jerry

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Look for one for a 76 or 77 Bronco. 30-2899 is a common aftermarket part #:
https://www.ebay.com/itm/1959216345...d=link&campid=5335857059&toolid=20001&mkevt=1

Also, you're looking for a Duraspark II setup, not the I. You don't have to run the larger cap / rotor setup, your existing cap and rotor will fit. The one I received was dual vacuum, so I removed that and swapped in my single vacuum unit from the old distributor.

For the ignition box - again, you want the Duraspark II module. It will have a blue plastic strain relief (grommet) crimped where the wires come out of it:
1750122740491.png


Then, it's just the matter of the wiring. Hit the junkyard, go the Painless route like I did, etc.
 

DirtDonk

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I will try and find a Duraspark I Dist and Red tab module some place in new or like new websites.
While the red grommet module may have some advantages, they don’t usually extend to price or availability.
Instead the blue grommet version like Jerry posted, usually has both of those covered. It’s the latest version and the most common in stores. And, at least in the past, was the least expensive as well.
I’m not one for buying on price, but the availability aspect could be huge. However, if you find a good deal on a red module, no reason not to try it. But I would keep looking for another one as a spare.
Because you probably won’t pick it up at the local parts store. Unless it’s an old store that is particularly well stocked.
 

DirtDonk

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Good luck with the parts. Sounds like a good deal. Should get you where you’re going. Interesting though, that even their pictures for the same part don’t match each other in every case. Some show the cooling fins and some don’t.

Before you install the distributor the first time, you might as well measure the non-ground wires to make sure it falls between 400 and 700 ohms.
Chances are very likely that it will, and likely that that installed part have already been tested.
But you can’t take anything for granted anymore. Many of the standalone parts are borderline.
Testing ahead of time just saves a little frustration later.
 
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wilcom

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thank you DirtDonk, which wires in distributor to measure? Gound wire to dist body?
Also, I will need a wiring diagram ( I can make my own harness). I think I also need a coil and resistance block according to some diagrams I see on the web. I thought the whole idea was for the Blue Tab module to take the place of the coil and resistor? I have a good pertronix flamethrower II coil I can use but dont know if this will be to much for the Module to handle?
FYI the Ford Parts Giant did not have the module in stock so I found it at https://www.autopartsprime.com/ford...mYpcgSRcY-WPRy9h7r_laXZpXQXG9F3v5DoNdYj7dUqNz
 

DirtDonk

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There are three wires in the distributor connector. The black with white stripe is the ground, that you can ignore for the moment.
Although do make sure that at least one of the internal support tabs is screwed down to the body of the distributor inside. You’ll see what I mean. That ground bonds the distributor to the module.

The other two wires, usually some variation of purple, orange, or green (but usually purple and orange) are the ones you wanna measure resistance between the two.
Should be that 400-700 ohms that I mentioned previously.
 

DirtDonk

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Also, I will need a wiring diagram ( I can make my own harness).
There are a couple of good ones here, one from Seabiscuit and one from Steve83. I’m sure someone will have a link to them.
Of course, you can also reference and aftermarket service manual. Which everybody should have who is working on a Bronco.
I think I also need a coil and resistance block according to some diagrams I see on the web.
Refresh my memory about your wiring. This is a stock, original wire harness. Correct?
If so, you already have the resistor built into the wire to the coil. Ford does not use ballast resistors in general, so most of their vehicles have a resistance wire.
I thought the whole idea was for the Blue Tab module to take the place of the coil and resistor?
Negative! The Ford ignition modules and distributor still require a coil.
You’ll see it in all the wiring diagrams. The coil is always necessary.
Even the HEI distributors have a coil. It’s just built in to the distributor itself.
I have a good Pertronix flamethrower II coil I can use but don't know if this will be to much for the Module to handle?
What is the exact part number on the coil?
For basic wiring, yes, the coil still gets the reduced voltage through the resistor wire. The module, on the other hand, and gets a full 12v.
 

ntsqd

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That grounded terminal inside of the distributor at the end of the black wire isn't just bonding the dist. to the module, it is the module's actual electrical ground. Can mount the module to a plastic fender liner, as Ford did on occasion, and the system will still work fine.

If a truly correct resto system isn't the goal, then I'd look at using the later model "E-Core" type of coil to use with the Dura-Spark II system. I ran one of these on a DD for a decade without a resistor wire.
 
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wilcom

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Thank you.
My Bronco engine is stock with RV off road cam, Fitech carb and Pertronix Flamthrower II distributor and coil. Wanting to change the Pertronix to Duraspark. Not trying to restore it classic oem, its my outback desert rig.
I remember way, way back when I bought it, it did have a ceramic type resistor block with points distributor before changing to pertronix. It was on the fire wall that is why I asked. So my plan is jut to Replace Pertronix with Duraspark distributor, module and coil. I have a pertronix 60104 flame thrower HV coil .45 ohms, 60K volts and flamethrower II round base coil 40K volts coil....can I use either of them?
Pictures of Chilton manual wiring diagram, rebuilt cardone dist and module so you can see what I have. One diagram is for the dist timing and how misaligned shaft teeth can cause timing issues if they are off. Question is (watch video), does the dist shaft teeth supposed to rub on the magnetic pickup as they rotate like mine does? So when engine is running it will make all kinds of noise....is this norma? The pic shows a gap but does not state there is one or how to adjust it if it does. 20230910_115727.jpg 20240921_163215.jpg 20241005_141900.jpg 20250717_095732.jpg 20250717_100051.jpg 20250717_100629.jpg 20250717_100639.jpg
 
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ntsqd

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No, the reluctor's lobes should NOT contact the pick-up coil! I've no idea what it is, but there is a spec for that air gap. You'll need brass feeler gauges to set or check it. Usually the pick-up coil assembly is riveted to the vac advance plate, so I'm not sure how you might be able to adjust it either. You may need a different whole dist. assembly unless you're willing to take this one apart and replace the pick-up/vac advance plate sub-assembly. If they're making contact it makes the whole thing suspect in my mind.

You won't need the ballast wire or resistor with either the GM module or the D-S II module, or the starting mode by-pass for it. Current thru the coil is not a problem like it is for points.

You may find that the starter wants to stay engaged after starting. I've only experienced one Ford that did this. It seems to be a combo of how you wire the start mode to the module and what starter relay you use. I know some advocate going to the later type of relay as a means of heading this off.

As I read that page about reluctor lobe alignment I think what they're saying is that each lobe must align the same as all of the others or you'll have cylinder to cylinder timing variation(s).

Broncobowshers' "formula" is my suggestion for the system as well. The reason behind the use of the GM HEI module is that D-S II modules are hit and miss. Seems like more misses reported these days than ever in the past. I honestly would use the dingiest, grungiest D-S II module that I found in a junkyard before buying a new one.
 
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wilcom

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Thank you ntsqud. I returned the distributor to the ebay seller due to it being defective and am now going to order directly from cardone but need to know if I should get the Steel or Iron gear.
Back in 1986 I rebuilt the engine and put an RV off road cam in it and still continued to use the old points distributor. In 2009 I replace the distributor with the Pertronix until this year I reciently decided to replace it with the Duraspark II dist. I believe the Pertronix are steel gears but cant verify that. The problem with the Pertronix is no spark at plugs (see original post) I did all the dist and coil testing, voltage/resistance, measurements with pertrnoix techs and even replace the flamethrower module twice, coil and new cap, wires and rotor, but still no spark. Just all the sudden no spark after 16 years of use.

Even if both the the cam and dist gears are worn I think I should still get some level of spark at the plugs even though it may be out of timing? Am I correct? The dist turns when engine cranking so I know its spinning and not a borken shaft or gear.

After reading up on the Steel vs Iron gears I find that if i use the wrong metal gear with the RV cam it could chew up the cam gear so I am wondering if the pertronix gear (steel?) ate up the cam shaft gear (steel or irion?) over the past 16 years to the point of being horribly out of timing and producing no spark. I dont remember the name and part number of the cam or even if it was steel or iron when they made them back then in 1987.
Pertronix did not offer steel or iron versions of the dist when I ordered it.
I am going to pull the distirbutor this week to check the shaft gear for wear before ordering a Duraspark II dist to make sure its not a worn gear issues.

Anyone thoughts on this?
 

ntsqd

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Generally if the cam is a roller cam then it needs the special gear. If it is a hyd. flat tappet or mechanical flat tappet cam, then it needs the regular gear. There are exceptions, and if in doubt I'd check with the cam mfg.
 

DirtDonk

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If you put in a cam back in the day, and continued to use the existing points distributor with no issues, it’s a flat tappet cam and needs an iron gear.
For a long time for Pertronix only offered the one type of gear in fact. Wasn’t sure if they had added new distributor part numbers or not. At one point, they offered a standalone gear that you could buy separately and add yourself.
Guess I’ll have to revisit their catalog

But the bottom line is, from the sound of your description, you need an iron gear.
Sometimes called cast, sometimes called cast-iron, sometimes just called iron. But compatibility with the cam material is the key.
 
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wilcom

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Got it. And yes I have the standard flat tappet cam. I will send pics of the gear when I pull out the Pertronix Dist.

thank you
 
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wilcom

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UPDATE; Winter set in and I could not work on her until 3 weeks ago. Decided to go a different route so I bought the Summitt 850075 magnetic pickup dist and a MSD 6AL box and Blaster 2 coil. wired it up and it fired first crank! Beware of the idiots at Summitt, they told me this distributor would work with the Duraspark II box and it does not! I called the tech line when I could not get it to even spark...the senior tech (13 yrs with summitt) said the counter people dont know anything about dist and they do no confirm its operations only what the computer says. Any way he said buy the MSD...ouch $$$$$

thank you all for your help...
 

DirtDonk

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Glad it’s running!
In their slight defense, depending upon the individual MSD distributor, the actual reluctor and stator are not only similar to the Ford Dura Spark, they ARE the Ford Dura Spark components!
So in theory, yes, those distributors with those triggers should work with a Dura Spark box.
But they don’t use the same connector, probably have other variations that would get in the way, and I don’t know what all else.

Yes the MSD 6 is an expensive little bugger. But, if it keeps running, it certainly is a good product to have.
I’ve heard plenty of horror stories of pretty much every brand on the market having failures more than desired. MSD included. But Dura Spark modules included as well!
So may you have many trouble, free miles.
 

ntsqd

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What makes you say it doesn't work? Most of those mag trigger distributors use Dura-Spark reluctors and pick-up coils. From the dist's page on Summit it comes with the unsealed MSD connector (that I despise!) installed, so it isn't a plug-n-play deal to connect it to a D-S II module. I've done it the other direction several times, driven an MSD box (because some continue to insist on using them) with a D-S II distributor. No reason why it can't work the other way around.

It is important to note that the D-S II loom connector at the dist. has three wires. Two are the sense wires, the third is the actual ground for the D-S II module. Without that third wire being grounded somewhere the D-S II module is never going to work.
 
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