It has been decades since I was in electronics school and I forgot a lot. I was told using copper plug wires could hurt modern electronic ignition parts, and I was wondering if an RFI capacitor (.5 mfd.) would help protect things. I have a 4-cylinder with points that have been changed to a Pertronix trigger...and that is electronic. The company recommends using modern resistance core wires, but copper has the least resistance to flow, giving a better plug spark...unless my old school thinking is also wrong.