I do have a 68 Charger which I converted to Twinplug, because it already had the Mopar alu twinplug heads. I took the old Accel cranktrigger type distributor which is empty inside, only the high voltage part there, and I converted the first distributor by adding a spacer and turning down the shaft inside, and adding a standard Mopar RB electronic plate + weights inside, adding a 2. pickup there, so one distributor makes the signals, and both deliver sparks. It works really neat, and gives extreme drivability, and starts really easy. In my manual 3:54 4speed car with stock mech cam, I can run from 10 mph in 4th, and accelerate fast up to top speed (at appx 6000 rpms), or my wife can take it to the grocery no problems.