Reply to "Duraspark I"

George is correct, the red and white pins in the in the 2 pin connector are the same for both the Duraspark I and II. It is the 4 pin connector where they are different. I did the complete I install this summer and discovered that two of the 4 pins are different on the I compared to the II schematics posted some time ago. If you search you will see my post with the correction. You can also go to Rock Auto and look up a DuraSpark I (CA Emission) and II (Fed. Emission) for a '77 Mustang V8 and click the link for the Airtex Wells brand boxes and it will show the pin out difference between the I and the II four pin connector.

By the way the DuraSpark I box works perfectly with no ballast resistor and a 0.7 ohm coil as it was designed to do. I have wound my 393 to 6500 rpm with no issues using a DUI re-built DuraSpark dizzy. It also works well with the MSD billet dizzy.

One other note as George's schematic shows is to make sure and provide the +12V feed through an independent relay that is controlled by the key but is supplied by the battery through a dedicated fuse. The I box can pull some serious current compared to a stock system.