I had to install a ballast resistor (in addition to the existing resistory) when I installed my electronic ignition in October 2003. I don't know if I have sufficient detail to help you, but you can check it out here:
http://www.banzairunnerpantera.com/updates_distrinstall.htm
I think I still have the wiring diagram from Dennis Quella that came with my distributor. I can look for it this weekend if you still need help. Let me know.
Cheers!
Garth
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