Check out my thread, I just rebuilt my 1973 Chrysler, and put 1985 Force ignition on it. I found alot of issues with my key switch. Check your grounds, all of them! From the neg battery cable to the starter solenoid, etc.. The thread was 1973 coil ignition to 85 force ignition if I remember correctly? It outlines some reasons why you would not have spark. Hope that helps?