thanks for the replies,i would use the duraspark but with an earlier 4 plug head, i have 3 efi mustangs right now but i wanted to mess with a carbed version with the carb adapter that bolts on to the efi intake,,just experimenting to make it simple,,there is a method running a 4 pin gm module with the duraspark distributor,suppose to give it a longer dwell with use of a the ford tfi ignition coil, will post later got to run