[RichardJ]

>> How the heck does the ignition circuit get it's electricity during cranking.<<

I've removed most of the unnecessary wires from this drawing. I'm showing four wires on the Ign sw, although only three are needed to start the engine.

Red 12 volt wire:
Follow the red wire from the battery junction block, past the alternator to the bulkhead connector. Inside of the bulkhead connector the red wire feeds the part of the fuse panel that is always Hot and feeds the Ign sw with 12 volts.

Pink 12 volt wire:
This wire is hot (12volts) when the key is in the Run position and the Start position. This wire feeds the inside of the bulkhead connector and plugs into the ballast wire that is in the outside of the bulkhead connector. This pink wire also connects to part of the fuse panel that is Hot in Run and Start positions.

Purple 12 volt wire:
This wire is Hot in the Start position only and connects to the "S" terminal on the starter solenoid.

Brown wire.
This is a resistance wire that is part of the alternator Exciter circuit. This wire is used for the original Ex-voltage regulator and connects to terminal #4 on the regulator. On a In-regulated SI alternator, this wire connects to alternator terminal #1. This resistance wire is the same if the dash has a idiot light or a ammeter. This wire is not part of the Run or Start circuit.

On a HEI conversion there should be no wire connected to the "I" terminal on the solenoid. On a HEI conversion where the whole world insists that you must remove the ballast resistor or the sky will surly fall, there is no reason not to connect the HEI to the bulkhead connector where you just removed the ballast resistor.