Had a set on a 1959 Ford back in the early '60's. Plugs were mounted into chrome tailpipe extensions (behind the bumper, the extensions stuck out beyond the bumper)and wired to a model T spark coil. Switch hidden under dash. No ignition mods, no carb mods necessary. Used not to show off, but to discourage tailgaters. Believe me, it worked. Removed when I sold the car. Jon.