Ford 200 Six Cylinder Duraspark II Conversion

Please be sure to heed the warnings about the Rally Pac tachometers and this system if you have one. There are very specific wiring modifications that need to be done to your car if you don’t want to burn up your Rally Pac. Instructions are at the end of this article before the parts list.

Author: Jonathan Campagna of the Vintage Mustang 6 Facebook Group

So this is a common question on the Vintage Mustang 6 Facebook Group, and I’d like to make a document providing insight and part numbers on how to perform the swap. If you find any errors in this document, or want me to add or clarify something, please don’t hesitate to let me know.

I’ll start by first saying, you have to decide if this is right for you. If you are modifying your intake/carb setup, this will work well for you. If you want to retain your 1bbl Autolite 1100, you can do this, but you have to find or make a ported/manifold vacuum source for the vacuum advance of the DSII Distributor. If you have a 2bbl swap, or the Holley Sniper 2300 EFI (or equivalent) Then this will be really nice for you.

You can run the DSII setup in a few different flavors. Later in this document, I will detail part numbers for each type of setup. First, if you want to use all Ford components, you will need a DSII distributor, control module, coil, and all of the factory wiring. You can get all of this in your local junkyard, or if you want new, the local parts stores carry the Coils/Dizzy/Module. The distributor should be sourced from a 1977 Ford Grenada with a 200CI motor. You can also get the cap/rotor/coil/module all from the same application. The wire harness is available in the aftemarket and is listed below.

The cap and rotor differ on the DSII vs the original points setup in a few key areas. One, the size of the cap is much larger, so you will need a new cap adapter for the top of the distributor. This is in the parts link. The cap itself is larger in diameter to give more of an air gap to keep from arcing to other terminals when the coil is fired. This is due to the much higher voltage, and higher voltage can arc to an adjacent plug terminal if the size of the cap were to stay the same. Secondly, the rotor is also larger in size to match the cap, and it has an increased surface area on the contacts to carry the increased spark current.

Plug wires from the points setup will no longer work, since they have different connectors, and are of different construction. The wires I have listed below are Motorcraft replacements, made for the DSII setup. They are a Carbon Core wire, and will work great for this, and give long service life. We’ve found that with the holley sniper setups that the MSD Super Conductors have the least RFI issues and I recommend this is what you use going forward if you have EFI. I would discourage the use of standard wire sets in lieu of the MSD’s.

If you want to go the total aftermarket route, you can use the same distributor, cap, and rotor as mentioned prior, and then use an MSD 6AL box and matching MSD coil. This setup will provide the hottest spark for both carb, and EFI setups.

If you are using the Holley EFI or equivalent, you will certainly want to use the latter of these setups, as it will allow you to run timing control from the EFI units.

It is important to mention that converting to this setup will require you to find a wire that provides a full 12v to the coil, and the DSII module in both run, AND crank. The original points style coil ran on about 6-8v, which will not give you full potential with the aftermarket setup. There are a few ways to remedy this. One way is you can utilize your original pink + coil wire to close the contacts of a Bosch relay, that you can then wire to power the coil full 12v. The premise being, the Bosch relay will be have the “30” terminal hooked directly to the battery source, and the “87” will carry the full 12v output to the “+” of the coil. Wire the original pink + wire to the “86” contact on the relay. Wire the “85” contact to ground. A second way you can do this is to attach a new wire to the back of the stud on the ignition switch. This stud has 12V power any time the key is on. If you do this, you still have to tackle the 12V in crank issue as well. You can run a wire from the “I” terminal on the ignition solenoid, and tie it directly to the coil “+” terminal as well as the switched 12v wire from the stud described previously. This will provide 12V in both the key on, and start position. These two methods can also be used for wiring the Holley EFI and the MSD box, which both need 12V in hot and crank as well. Note that the wiring for using the MSD box is different, so make sure you are using the correct diagram! They are both shown below in the figures!

As far as initial timing, and total timing is concerned, the factory curve on the DSII distributor should be ample for most people’s setups. If you properly set the initial timing to 10-12* BTDC, there should not be enough total advance to do any engine damage. The distributor mentioned in this article has a total of 26 degrees mechanical advance built in. 26 added to your 10-12 initial is 36-38 degrees total, all in. The factory Ford curve is going to be very conservative, as they wanted to eliminate any possibility of knocking or pinging. You really don’t need a recurve on these distributors, but if you really feel so inclined, here’s how to do it:

https://www.reincarnation-automotive.com/Duraspark_distributor_recurve_instructions_index.html

For timing control If you are using this setup with the Holley Sniper EFI, you will need to disassemble the top of the distributor and lock out the mechanical advance weights. There are a few ways to do this, but I found the most effective was to use stainless lockwire to tie the weights to the rotator plate. Then follow the instructions on how to stab the distributor in the Holley manual.

As far as tachometers are concerned, if you have a modern aftermarket “voltage triggered” style tachometer, you can hook it up as per the instructions included with the tachometer. Typically there is a 12v switched wire that provides power to the tach, a ground wire, and a trigger wire that gets connected to the “-” terminal of the ignition coil. You can also use the “tach” output on the MSD 6AL box to trigger the tachometer

Check out https://amzn.to/4beXDES for a 12v relay.

If you have an original Rally Pac, you MUST hook it up with a tach adapter, MSD part number 8920 or equivalent. The reason is the original tach is a current triggered device, which is in series with the ignition switch, through the resistor wire, and to the “+” of the ignition coil. If you leave the factory wiring hooked up with the Duraspark or MSD, you will burn your tach to smithereens. See the 4th figure below for wiring.

DURASPARK module wiring only. I have modified this schematic to OMIT the resistor wire to the positive side of the coil. This is how it should be installed on a DSII setup 

MSD setup wiring

Now that you have all this spark potential, remember to increase your plug gap as well. Anywhere from .044-.054 on the gap with DSII ignitions.

So now on to the parts lists:

If you are not going to use an MSD box and want to use a factory Duraspark module, you need all of 1-9 Below. If you are going to use the MSD box, you need ALL below except item 4 and 5.

Use the part numbers to find your own sources if the links don't work.

Bone Stock:

Distributor : A-1 Cardone 302690 - Amazon or https://www.summitracing.com/parts/aaz-30-2690
Cap and Rotor Kit - NTK 3D1109A – No longer available. ’77 Ford Grenada 3.3L for application. Get from parts stores locally. https://amzn.to/4jZspnj
Coil - MSD 8202 Blaster 2 Hi-Performance Coil; I recommend even on a bone stock setup to run an MSD coil for extended life . If you order the 6AL box below, you will not need this as it comes as a kit. https://amzn.to/4qi9uGd
Module - Motorcraft DY-893 https://www.rockauto.com/en/parts/motorcraft,DY893,ignition+control+module+(icm),7172
Harness - Either junkyard, or here: American Auto Wire 500918 https://www.summitracing.com/parts/aww-500918
Wires - Standard Motor Products 6620 https://amzn.to/4ae1mS3
Plugs - I’m running Autolite AP46 platinums, but you can run the plug of your choice. Just remember to increase the gap to at LEAST .044, if not more, up to .054 to account for the hotter spark. I recommend against the copper plugs, I had issues with them and misfires. https://amzn.to/49TCFcf
Cap Adapter - Needed to run the new DSII larger cap. Wells 4D1002 https://www.rockauto.com/en/catalog/ford,1977,granada,3.3l+200cid+l6,1129890,ignition,distributor+cap+adapter,10738
Tach Adapter: MSD 8920 . Needed if you have original rally pac ONLY https://amzn.to/3LSX3SM

MSD Parts:

MSD 6AL Box . Coil is listed above in #3 https://amzn.to/4rb5dVD
MSD Ford Distributor Plug Adapter - Needed to cleanly attach the Ford Distributor to the MSD box https://amzn.to/4qz8qyq