Finding switched 12 volt source

yellow rose said
I guess now I’m at the point I need to decide where to grab the 12 volts from, doing the least amount of damage to the OE wiring.

I’m thinking I may just pull the power off the fuse panel. Not sure if that is the best thing to do, or even a good thing...but that’s where I’m thinking I may get it at this point.

Any objections to this? If I’m thinking correctly, if I pull the power from the fuse block, I can leave the wiring at the ballast resister plugged in and just unplug the OE ignition box.

Of course, I could be nuttier than a jar of goobers too.

Now I'm lost.
I thought you were looking for a switched power source to turn on the box?
Are you now asking about the main power? No switch, no fuse. Direct heavy wire to a power source.
Mallory shows it to the battery, but note it can be any place in the line such as the starter relay (or for a Ford, the solenoid).
Also on the first page it says it does not matter if the ballast resistor is present on not. So its same as the MSD

This diagram is most representative of a Chrysler distributor.
When it says ballast not used here, its in reference to the coil. The Hyfire needs to be directly wired to the coil - no ballast in between.