There are also resistor spark plugs that install on the ........end.

Thus, many options to introduce resistance in the high voltage system.

If unsure, begin with metal conductors and the Beru resistor plug connectors or just resistor spark plugs, then add more of them if radio reception is an issue or if the electronics goes wonky (not exactly a technical term). Or begin with a ***** load of resistors, then delete until something falls off (e.g. performance and/or wi-fi/Bluetooth signals). Let's not get too "FCC" about this. They're just plug wires.

Sherwood

It's a vintage racecar, actually. The only electronic anything I'd worry about is the crankfire ignition, as it turns out. I'd hate for the ignition to interfere with itself!

I can't tell what the existing wires are, but I suspect they're solid core wires. I'm going to cut one of the old ones to check, and also confirm that the coil connectors aren't resistor (I think they're not), and then just duplicate what's already on the car - it seems to be working ...

Scott

Or you could avoid cutting and have a bunch of good spares, just in case.

To confirm, connect an ohmmeter to both ends. Metal conductor = 0 ohms. Earlier Beru plug connectors were screw in and possibly resistor-type. Remove and test wire and connector separately (the plug connectors sometimes go belly up too).

Sherwood