I'm converting my 67 to petronix ignition. I know per the instructions that the module needs 12 volts. It also states that if your original coil has a resistor to leave it that way. Ironicly though they don't tell you what voltage to use on their Flame Thrower coil? I did a search on this and got mixed results. Does anyone know what voltage to run to this coil? Thanks so much for any help.