By "fender mounted module and resistor" I assume you mean the factory Mopar ignition c.a. 1970's. The biggest advantage is that you can run a better E-core coil with much higher primary current. There has been much progress in semi-conductor design since the 1970's. That gives a much more powerful spark, aka "HEI ignition". You can then gap your plugs up to 0.060" for better combustion, especially with leaner mixtures if you want more economy.
