I am currently rebuilding a '67 Mercruiser 160 and want to convert to an HEI ignition. I have a coil with an internal resistor for the new HEI distributor, so I don't think I need a ballast resistor. The coil is not in the cap, it's seperate. Does this mean I only need 1 wire from the key and not one from the starter solenoid? This is how I understand the "old way": when the engine is started, the coil gets 12V from the starter solenoid, once the engine started and the key is released, the voltage now going to the coil is ~9.5v going through a balast resistor. Being that the new HEI coils have internal resistors, I am thinking I only need 1 wire from the key to supply 12v and another for the tach. Does this sound like I have a good understanding so far?