Plugs and Wires

Solid wires / R plugs will likely cause radio noise

Some ignitions do not recommend solid wires. I believe this has more to do with radiated interference than anything else. That is, some modern ignitions "bang" the spark pulse so hard that they generate a powerful electromagnetic pulse, made worse by solid core wires. This radiated power can interact with other systems, not excluding voltage regulators, EFI, or just about any other electronic system. They can also cause false triggering of the ignition system itself

I would not use a projected plug unless the application catalog for that engine recommends one