[Ronbo]

Nope, ballast resistors were only required on point ignitions as points could leave the coil continuously energized while the engine was not running and the key was still "on". By design electronic ignitions can't do this.

GM (starting around mid 60's) used a NiChrome wire from the firewall block to the coil so there was no visible resistor. Far as I can recall Ford and Chrysler used either a resistor or a built-in ballast in the coil.