Just to close the loop on this. After extensive testing, isolating this and that, resistance checking this and that....that I can now conclude.....
It doesn’t matter.
This quest started with me thinking I had too low voltage from the ballast to the coil. I had in my head that less than the textbook 8-9 volts might be causing weak or unreliable spark.
4.5 volts from ballast to coil = bright white spark from distributor wire while cranking that will easily jump 1/2” or more. This setup was the new ballast that is 2.2 ohms and the wire from the starter to coil disconnected.
5.6 volts from ballast to coil = Same results and this is how I chose to leave it. The old ballast registers about 0.6 ohms. Starter to coil circuit disconnected.
If nothing else, all this silliness made me much more familiar with the entire ignition circuit. It also gave me occasion to clean up some sketchy looking terminal connections and throw some shrink wrap over ancient crusty wires with cracked insulation from the 50s.
Thanks to all for your input.
