These 40,000 volt, 1.5 Ohm Flame-Thrower canister coils can benefit virtually any distributor type inductive system. Its higher voltage allows larger spark plug gaps for added power, smoother response and better fuel economy. They are oil filled for great heat control, and internally resisted. Legal in all 50 states and Canada (C.A.R.B. E.O. #D-57-10). Point Type Distributors: For 240Z's with points, DO use the stock Ballast Resistor with this coil. This Pertronix is a 1.5 ohm coil, and the 240Z had an original (Coil + Ballast Resistor) resistance of approximately 3 ohms. If you use this coil without the original Ballast Resistor, your resistance will be too low. If you wish to remove your original Ballast Resistor, you should instead choose a 3.0 Ohm Pertronix Coil. Factory Electronic Ignition: 1974 and later Z's with original ignition should use this 1.5 Ohm coil as opposed to the PerTronix 3.0 Ohm coil, and also should retain the stock ballast resistor. Aftermarket Ignitions: For the PerTronix Ignitor system, PerTronix recommends using their 3.0 Ohm coil, and not using a ballast resistor. If you are using a PerTronix Ignitor, and keeping your ballast resistor, use this 1.5 Ohm coil instead. For other aftermarket ignition systems, please check with that ignition system manufacturer for whether a 1.5 or 3.0 Ohm coil will work best.