Tnx for the info Pete, never heard of it before but will give it a try. My pro mech. has come up with a hotter than usual in the meantime so going with it.Difference between a 6 and 12 volt coil................far as I know both are specifically built for 6 or 12 volt. Is there any other factor here? We did try a MSD 12 volt on it and it cleared up the problem immeadiately but are thinking it will mess up the 6 volt ignition system. I did run the car for about 5 years with just a standard 6 volt coil and worked fine until this summer. Like the Toolman says "more power".