Carbon tracking through rotor. More HEI woes.

^^This is true but the more gap or resistance in the secondary circuit, the higher the coil voltage climbs. Similar to lightning, looks for an easy place to go.

1....CAREFULLY inspect EVERY part of the secondary (high voltage system) to look for high resistance or spark gaps. This includes poor plug wires and or coil wire. It also includes plug types with "trick" gaps or even a bad plug. It HAPPENS

2...Rotor phasing. If the rotor does not track the tower contacts when the spark fires, there will be a big gap between the rotor contact and the associated tower contact, and it will look for "somewhere to go."

Lacking that I'd look for better quality rotor and "if you can't find" then investigate say, some thin teflon or other high voltage insulation in thin sheet form that you can lay on top of the dist. shaft under the rotor

High voltage gaps TAKE OUT HEI and other modules. For example, NEVER allow an electronic system to fire, either cranking or running, purposely, with a plug disconnected. The high voltage pulse on that open circuit will backfeed or reflect a pulse back into the electronics