I have a '64 230 sl. A previous owner installed a Crane XR 700. The original ballast seems to be connected to the ignition switch. There does not seem to be ballast between the Crane module and the dist. I've replaced the spark plug wires with ones that meet the original specs (solid core with resistance at spark plug boot). After reading up on the XR 700, it seems that different wire is needed. Anyone have any comments or suggestions? I'm having a problem with plug fouling. Thanks Chuck