Do you have to have the pink resistance wire?

You could have asked it the other way....you don't need the ballast resistor if you use the pink resistance wire...only need one or the other..

The mustang wiring is designed to put the full 12v on the coil for starting though. If you use the ballast resistor, you'll always have 9v at the coil, even while cranking.

get a 40,000V Petronix Flamethrower coil and Petronix Ignitor electronic ignition and forget the ballast or resistor wire