Duraspark II questions
 

I've got a 86 F150 300 4.9l that I am wanting to convert to the Duraspark II ignition. I am wanting to know what parts I'm going to need to do this. I know I have to have the wireing harness, coil and the igntion box. Can I use my current Distributor or need to get a different one? If I need to get a different one do I need a single or dual vacum? I was going to get all the parts from a truck in a junkyard but haven't had any luck finding any! I think I am just going to buy new if I can figure out what parts I need. Any help would be appreciated.

You're asking all the same questions I would have asked. That's good cause now I can just sit back and read your threads and find out all the information I need. ;)

I am not positive but I think you can keep the distributor you have.

Check this out...
Classic Inlines Performance Parts - Duraspark Swap

Jim

If I remember correctly, you'll need a different distributor. On the 86, the distributor was advanced by the computer, whereas the DSII setup was advanced by a vacuum line. A new DSII distributor is pretty cheap, about $50 - $70 depending.

Here is a thread with info

https://www.ford-trucks.com/forums/9...5-86-4-9s.html

You will need a new Dist.
Auto Zone has a new dist. single vacuum with cap and rotor (no core charge) for $71.99. You can get a rebuilt for less but will need to buy a cap and rotor as they are different. Not sure if they will take yours as a core as they are a different style. I used a new dist when I converted to DS2 as the junk yard stuff was over $25 and all worn out.
It will be a good time to change the spark plug wires as the coil wire you are currently using will not fit in a round coil.
I also pick up a DS2 module on my last Junk Yard trip, it is a Napa TP 40 module, it is a rare find in the junk yard and the only module I would bring home from the yard. They cost about $90 and are one of the best. You can get a DS2 module for a lot less, say $30-$40, but you get what you pay for. If you think you might want it I can take it to the auto parts store and get it tested. I also have a couple of coils on hand.

Jim

Do I need a round coil or a Square coil or does it matter?

You're gonna need a round coil bud, unless you switch to the GM connectors like our friend JimsRebel here.

Thanks for all the help everyone!

I put an '86 300 into my '79 Bronco, and swapped it to DSII. I bought a DSII dist. (local part store <$60 4 years ago), used the '79's spark box, wiring harness, and bought a pigtail assembly so I could use the square coil (again local part store <$20). Because the Bronco already had a DSII in it for the 400, I didn't have to worry about any "step down" in voltage from the run position, since it was already built into the stock wiring. FWIW, I also used a '76 Carter 1bbl carb non egr, and manual choke to keep things simple.

If you decide to get a new distributor, consider our custom curved Duraspark Distributor built with our new Full Length Oil Impregnated Bronze Bushing. The full length bushing improves timing stability and spark scatter. If stock appearance is not an issue, take a look at our one piece D.U.I. Distributor. Whether you choose the Duraspark or the D.U.I., we curve each on a distributor machine based on your engine combination. Please see them at:

http://performancedistributors.com/forddistributors.htm

Also, there is now an excellent installation article on the D.U.I. Distributor on the Ford-Trucks.com site at:

https://www.ford-trucks.com/article/idx/0/358/article/DUI_Ignition_Installation_In_A_Ford_351W_V8.html

Ignition Lesson of the Month: Hystereses, the difference between the timing as the rpm and vacuum increases to the timing as rpm and vacuum decrease, needs to be kept to a minimum. A precise advance curve accomplishes this.