Ballast resistor Q's

I’ve been doing some research on this very subject for my own education for reasons unrelated to this thread. From the 1973 Factory Service Manual (FSM), in reference to the dual ballast resistor using electronic ignition, (note: the compensating side of the dual ballast resistor is the side that is in series with the coil positive): “The compensating resistance serves the same purpose as in the contact [points] ignition system, that is to maintain constant primary current with variation in engine speed. During starting this resistance is bypassed, applying full battery voltage to the ignition coil…”

Here are a few more useful specs from the FSM:

Coil (Essex 2444211)
- Primary Resistance: 1.41 to 1.55 ohms
- Secondary Resistance: 8000 to 10200 ohms

Ballast Resistor (resistance @ 70F-80F)
- Compensating side (coil side): .50-.60 ohms
- Auxiliary(control side) (note: not used with 4-pin ECU): 4.75-5.75 ohms

Current Draw (Coil and Ballast Resistor in circuit)
- Engine stopped: 3 amps
- Engine idling: 1.9 amps

What I have learned from reading various sources is that the Coil, the Ballast Resistor (or no ballast resistor) and the ECU must all be considered when selecting components. As others have said, some ECUs (for example HEI) have an internal current limiting circuit so they do not need a ballast resistor. If the manufacturer calls for a ballast resistor (Mopar and others) it is there to maintain an acceptable current level for the coil so it does not overheat (and to allow hotter spark for starting). One last point, race only vehicles and street driven vehicles have different requirements, so don’t get all twisted.

I know of one article on the web from Mopar Muscle that states if you have electronic ignition you can remove the Ballast resistor because they are there for points distributors. In my opinion that is a very misleading statement.