I am converting from my worn out durapark ignition over to the MSD setup. I have been overly hesitant to step up to a full MSD system but I am parting ways from my reservation of absolutely keeping the duraspark on my 351C.

I just wish I understood what FoMoCo was thinking with the 72-early 73 cars and the Positive ground versus the 74-79 cars on the tach. Sitting here trying to make sure I get the correct tach driver for this.

Really sort of annoying.

I was debating about keeping my duraspark ignition box but after 27+ years...it's time to upgrade to new system.

I just wish I knew if I should remove the original resistor wire or leave it alone.

one would think I have no reservations about changing my wiring yet again...but man, I just don't want to mess up and fry stuff.

Edit:

Now that I recalled why I made this post: Ignition coils. 

TFI EEC IV coils, versus the traditional coil. I was considering using the more modern type coil from 92-96 F series trucks. 

Specs on the stock motorcraft and the MSD look comparable. 

Plus...this will sound really stupid but I HATE the red color.

 

I am searching the ole interwebs on what I need to do converting over to the TFI coil, but if anyone has advice, just wanting to avoid mistakes.

 If you hate the MSD red, tape off the terminals and paint the MSD distributor cap Ford blue engine paint-I found VHT paint works best(or whatever color you desire), I've been doing that for a while since using Accel dist caps(they have brass terminals)don't like the tan color . The TFI coils require full 12V at start and in run. When I cobbled together my ignition system, I used the original resistor wire to trigger a relay that sends 12V to my TFI coil, even with reduced voltage output it still energizes the relay and can easily be converter back if later in life you want an all Duraspark ignition. Hope this helps 

I wish you well with the ignition system, that seems to be an issue for most of the older cars. I never had trouble with mine in the 70's and 80's when I sold my 72.

I have the Mallory system parts I bought when I was young and had my 72, but I never installed the Hyfire IV box, or the coil. I liked the Unilite distributor, but ages later people bashed them. I kept that too when I sold the car, I intend to put all of those on one of my 351C's.

I'm watching with interest for more good news about what works these days.

Eliteman76 wrote: I just wish I understood what FoMoCo was thinking with the 72-early 73 cars and the Positive ground versus the 74-79 cars on the tach. Sitting here trying to make sure I get the correct tach driver for this.

maybe the 1st time i've heard it referred to as positive ground? what it does is the coil power flows through the tach, thus only 2 wires In & Out. the later 3 wire tach is similar to aftermarket tachs that use switched 12v power, a coil + signal wire and ground. i don't believe there is a way to use the Ford 2 wire tach with MSD? either swap out the 2 wire tach for a later 3 wire or get the 2 wire tach converted by a gauge outfit with an aftermarket make-it-happener

https://www.summitracing.com/parts/MSD-8920" rel="nofollow - https://www.summitracing.com/parts/MSD-8920

Biggest issue was wire color on the 8920 and then the Digital 6AL ignition box were different. But the diagrams in the 6AL manual helped me square things up and get it wired. 

https://www.summitracing.com/parts/MSD-64253" rel="nofollow - https://www.summitracing.com/parts/MSD-64253

I connected it into the wiring to the dash and called it a day. 

Completely removed all the factory duraspark stuff.

With my GTS, I am using a 72 rally cluster so it has the goofy positive ground setup. 

Then to make your head hurt a bit more, I adapted the Duraspark off my '76 Elite using the Elite's engine harness for the Duraspark connected to an NOS harness for a '75-76 LTD. Distributor came off a 1977 T-bird with a 400. 

I pulled from a few sources to ditch points back when I was getting the electrical stuff sorted out. 

I did things...that I look back and want to smack myself for over complicating things. 

  

I only went full MSD due to the 393C stroker I took in trade for money owed to me that I ripped the top end for my CJ rebuild. 

but I will tell you the first few passes on the CJ before the bottom end ate itself...that CJ was scary man. Absolutely scary. Here's to good thoughts on the round 2 rebuild being faster and lasts a lot longer than...20 miles.  

I interested in them.

I am currently selling the Duraspark ignition stuff with my 1971 351C 2V engine. 

If you need a durspark harness, Painless sells a brand new harness that's worth using.

https://www.painlessperformance.com/wc/30812" rel="nofollow - https://www.painlessperformance.com/wc/30812

With that said, I've read over the years about the Pantera guys discussing the later Duraspark 1 (Duraspark I) systems, meant for California emissions stuff and also I believe ditches the need for the ballister resister. I by no means an expert on Duraspark...I just adapted what I had laying around and made it work.

Who might now how useful a Mallory Hyfire IV would be, and the matching large coil? I have two ignition systems I might use on my 351C, likely a stroker running maybe 6500rpm. The Mallory parts I have are new, except the Unilite distributor I ran for a few months on my first car(351C-4V). I think it should survive the rpm.

My other system was a Jacobs I had on my 91 Mark VII, stockish 302 with heads and intake, 5500 shifts. I liked that system, but it was no gain over stock. I wrecked that car and saved almost everything. Just thinking, I read the OEM distributors are the best, and the Duraspark is very good compared to aftermarket. I'm open to any new news.

After a few more trials and tests...I can say I am more than pleased with the MSD Pro-billet distributor.

One thing that really helps me with the fact I have a GTS ram air hood, the MSD distributor does not suffer the issues my Duraspark unit was prone with getting water inside of the cap and leading to pulling the cap and cleaning out.

I still would really prefer to replace the vac advance bushing with my 10 or 14 degree bushing but my engine pulls so well under just mechanical advance I'm not interested in touching it currently.

I've got both an MSD setup and a recurved duraspark setup off a 460 on the shelf. The msd setup does not have a vac advance, so that's what I'm leaning towards using because I think I'll try locking it out and then using the timing map feature of the fitech tbi system. I just hope I don't have too much interference that it causes the throttle body to go wonky.

I assume you've got the small cap distributor? I've got the large cap msd distributor which is similar in size to the duraspark. How difficult is the vac advance bushing? I redid the mechanical advance bushing in my msd and also did the plate weld/grind on the duraspark. Both required distributor disassembly, so if it's running good, I too would hesitate to change it.

Interesting that the hood was pooling water into it. Do you have block off plates on the hood or a ram air setup? I'd like a sport hood with ram air if I can find it.

Water issue was no block off plates, and the duraspark parts store replacements with less than idea sealing.

The MSD requires pulling the shaft out, I have not looked too in-depth at it.

There is a guy making specific bushings to limit timing movement.

Part of the headache is the vac canister. It pulls timing in WAY too fast.

Glenn tweaked the springs for the mechanical advance, and it’s run about flawless tbh.

I just think the vacuum advance would improve part throttle mileage.

I looked into it it was possible to swap a Duraspark canister on a MSD, figure a stock Duraspark and this MSD look pretty similar.

Tbh, 

from experience, any opening in the hood eventually results in a junk yard looking engine bay

the Ford dizzy boot

Now that I am running my MSD distributor that is firmly screwed down, I've not experienced issues like I used to with my duraspark setup. Part of my issue stemmed from I was using a small cap and rotor setup instead of the large cap and rotor due to my air cleaner. Found that I needed to always place a bag any time I was washing my GTS at a car wash. No issues if I was out driving through rain however.

I know over the years of doing multiple hot rod power tours and other long road trips with my old 351C and the duraspark, if I did run into issues, I always kept a multi-screwdriver (type that you could flip the bit Phillips to regular) and just pop the air cleaner loose, snap open the clasps and wipe out the cap and rotor with a little shot of Sprayway glass cleaner and wipe out with a towel or rag and good to go. 

Old trick I always heard was a shot of WD40 in the cap but never tried that to disperse water...something about sparks and a flammable solvent never sat well with me 

https://youtube.com/shorts/sSTUdQHTwQ8?si=ZBMYS_3Gj0te7Lkr

 

Don, I will tell you for the older Mallory stuff I would hands down run it. I hate the fact the Holley group bought out Mallory basically to just eliminate a competitor. Especially when mallory was USA based product.

I was not super enthused with MSD being China made on basically everything these days. Time will tell I suppose. 

Honestly, another option I like to reference is DUI Davis Unified Ignition. 

They do some really nice Duraspark stuff, and let's be honest, over the years plenty of folks have found Duraspark will cover up to 600HP applications, just make sure the distributor gear matches the camshaft application. 

So far I am pleased with the MSD setup. but run what ya brung man, and hope ya brung enough 

Of course finding one these days new might be a headache. They had a nice ball bearing design on the rotor shaft for marine higher rpm duty.

https://performancedistributors.com/product/ford-hot-forged-dui-distributors/" rel="nofollow - https://performancedistributors.com/product/ford-hot-forged-dui-distributors/

Ignore the red distributor cap, they also have a blue hipo cap for their units (and not the MSD/Chevy red.