Converting Stock Distributor Cap

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I'm currently running a stock cap and rotor on my Duraspak distributor which has the traditional female socket brass terminals and side clamp-downs. I'd like to convert the cap and rotor to male HEI type terminals. Specifically, I was thinking of purchasing the following, which is available from Summit:

* Davis Unified Ignition 32100BL - Davis Unified Ignition Cap and Rotor Kits. Cap & Rotor, Blue, Male/HEI, Brass Terminals, Clamp-Down, Ford, Duraspark, Big/Small Block, V8, Kit

Does anyone know if this conversion is a straight swap with my stock cap and rotor on my stock Dura Spark distributor and is there room for the larger cap and Rotor.

Thanks for any help.

Rob

 

[blubuckaroo]

The big cap and rotor is interchangeable with the small one with the use of the adapter funnel.

It looks like the adapter is included in that kit.

 

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Thanks blu!

 

[jckkys]

The large diameter cap was the stock OE cap on '77s. They were blue with blue adapter and rotor.

 

[ntsqd]

Rock Auto:
Cap Adapter $5.80
http://www.rockauto.com/en/moreinfo.php?pk=43727&cc=1105591&jsn=421
Cap $22.99
http://www.rockauto.com/en/moreinfo.php?pk=385873&cc=1105591&jsn=428
Rotor $7.41
http://www.rockauto.com/en/moreinfo.php?pk=385896&cc=1105591&jsn=436

Total $36.20 + ride. Assuming the DUI parts are quality that's not bad. I tried to choose quality parts over price, could pick the cheap stuff and likely get under the DUI price, but why?

 

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Right on! Thanks for taking the time to list the parts Brother. Much appreciated.

 

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Okay, one last question. When I convert to male terminal type distributor cap, must I convert the stock style female coil as well? Or do manufacturers of Ford Motorsport spark plug wires supply a coil plug that fits the traditional female coil?

I hope that makes sense.

Thanks for any help.

Rob

 

[jckkys]

The coil end of the wire was unchanged in '77. Only the distributor end changed on stock '77 plug wire sets.

 

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Thanks! I appreciate it.

 

[ntsqd]

Some ign cable sets come with two coil wires, one tower-tower, one socket-tower. If you've already got D-S II I'd change the coil too. Could also buy the MSD converter if they still make it.

 

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I might go ahead and change the coil as you suggested. I do have a Dursspark 2 and my current location for the stock coil is flat on the intake manifold. I've never liked that location, but I'm also not particularly excited about moving ito either. But i may have to do it. Any other suggestions on specific coil as a replacement?

Thanks again.

 

[ntsqd]

My own preference is for the stock TFI application E-core coils. Ran one for years on my then DD '67 Ranchero. You'll need the OE connector for it.

 

[mpboxer]

I might go ahead and change the coil as you suggested. I do have a Dursspark 2 and my current location for the stock coil is flat on the intake manifold. I've never liked that location, but I'm also not particularly excited about moving ito either. But i may have to do it. Any other suggestions on specific coil as a replacement?

Thanks again.

About a year ago I was looking into making the same conversion as you, but eventually just decided to stick with my stock style cap and plugs. My original coil (which I believe was stock) had the horseshoe type connector on it and that connector needed replacing and for some reason I couldn't find the connector or it was too expensive or whatever, so I just went with the MSD Blaster 2. My local auto parts store had it in stock. Haven't had a problem since. I thought I read somewhere that the coils like to be somewhat vertical and kept cool. My alternator bracket might be different than yours, but that's where I mounted mine too.

 

[savage]

I converted my 74 to the larger cap and bought the ford racing wire set and it came with the right coil to cap wirer. Then I converted it to the Duraspark II blue grommet box, with a MSD Blaster SS Coil.

 

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Thanks guys. You've given me great info. And the the pictures look great.

Rob

 

[dbruce9035]

About a year ago I was looking into making the same conversion as you, but eventually just decided to stick with my stock style cap and plugs. My original coil (which I believe was stock) had the horseshoe type connector on it and that connector needed replacing and for some reason I couldn't find the connector or it was too expensive or whatever, so I just went with the MSD Blaster 2. My local auto parts store had it in stock. Haven't had a problem since. I thought I read somewhere that the coils like to be somewhat vertical and kept cool. My alternator bracket might be different than yours, but that's where I mounted mine too.

+1 for the msd blaster 2.
Unless you know what you're doing I would stick with the MSD or stock coil. When I changed mine, I fried four coils before getting MSD Blaster 2. I even ordered one through one of the Bronco suppliers. Told them I had the duraspark two ignition and still got the wrong coil.

 

[ntsqd]

In an oil filled coil I prefer to lay them over so that the oil coats all of the terminals and helps cool them too. Maybe that is a remnant of my air-cooled days where if you didn't do this you'd cook the coil because they were internally ballast-resisted and isn't a requirement for other coils, but I've never had one fail when doing this. Both of the "yellow-tops" on my '67 Mustang and on my '67 Ranchero were mounted horizontally. Could be coincidence, maybe not. Ran the Ranchero with that coil in the assumed stock location for thousands and thousands of miles w/o issue. Only reason it didn't go longer was the conversion to the D-S II large cap and I wanted a coil to match those tower terminals.

They work, but put me in the "Not a fan" camp with regard to MSD products. It takes a good argument to sway me from OEM electronic ignitions (excepting early Mopar stuff).

 

[DirtDonk]

According to some books, oil filled coils (at least the aftermarket ones) need to be vertical for reliable cooling. But as anyone who owns a vintage Ford like ours has seen, they came laid over, or almost over flat from the factory and were some of the longest living old style coils on on the market.

The hope is to keep as much oil covering the coil windings as possible, and if a particular coil is a little low from the factory, laying it on it's side runs a greater risk of leaving too many windings exposed to air.
It's likely Ford's OE supplier was tasked with keeping them full of oil and not letting any get through with less than specified levels.
In the aftermarket, there's not so much pressure to be so consistent sometimes.

And in our applications at least, they expected plenty of cooling air from the fan to be blasting over the coil even though it was mounted to a hot engine.

Traditionally shaped can coils with epoxy filling instead of oil are supposed to be both more vibration resistant AND resistant to heat damage, even though the epoxy likely isn't quite as good a coolant as oil. But maybe it's a special epoxy that has better than normal conducting properties?
Dunno, but they're usually recommended for air-cooled and off-road applications by their manufacturers.

Paul

 

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Update - Rotor does not fit

So, I ended up purchasing the following distributor cap conversion kit from Summit Racing to upgrade my stock cap and rotor:

Davis Unified Ignition Cap and Rotor Kits 32100BL

I finally got around to installing it today with pretty blue wires and it turns out the new rotor is too small for and does slip on distributor shaft. Has anyone run into this and can I find a replacement rotor at local auto parts that might work. I was so frustrated I almost opened up the i.d. a bit to get it to fit, but thought better. I thought these adaptors kits were supposed to be a straight swap?

Bumming out

 

[DirtDonk]

Well that sucks a big one. Never heard of it because all the distributors I've seen all used the same size shaft up there. Or at least I thought they did. Maybe one of the guys that has been around working on Fords longer can confirm or deny that though.

Maybe DUI is actually sourcing themselves some Chinese crap now. Or maybe they always have and just put the distributors together here in the US?

Did you call Summit and ask them for a replacement yet?
Any chance you have some sort of insert on top of your existing shaft, or a piece of the old one popped out and stayed with the shaft? Or is it bare metal all the way?

Paul