We have an 1989 Fox with a failing TFI distributor and we'd like to change over to a DuraSpark distributor. Does anyone have guidance on how to do this? Which distributor gear do I use? the one from the TFI we have now or the DuraSpark one? What about wiring to the MSD 6a box?
The DuraSpark unit is not compataible with EFI, it has a mechamical spark advance. The EFI distributor has no spark advance mechanism, it uses the computer to control the spark advance.
Instead of using the battery negative terminal, attach the heavy gauge black wire to the body ground point by the windshield washer filler.
The battery common ground is a 10 gauge pigtail with the computer ground attached to it. Picture courtesy timewarped1972