Okay I got one for you. I just got a new 6 gauge cluster for my 66 stang. I've got a 289, with the pertronix ignitor. To hook up the tach, it says hook the lead wire to the positive side of the coil. If I do that it goes to max and stays there. negative, it does a similar dance. The instructions said that I need a convertor or something if it has electronic ignition. So what do I do? Do I need a convertor? I have the tach set for 8 cyl.