[davepl]

I'm not up to speed on 6-cylinders, but the for 8s you normally have two hot wires to the coil. One comes from the starter, and it provides a full unrestricted 12V but ONLY during cranking. You also have a second one, white in most cases, that comes from the ignition switch. This wire is itself the "ballast resistor", because it has resistance built into it.

With HEI, you do not need both. You are going to supply only one (though the second, from the starter, won't hurt anything), and it needs to be a full 12V. This means you cannot reuse the existing ignition switch wire, it must be replaced.

The easiest way to do this is to run a new wire to the "IGN UNFUSED" terminal on the fuseblock and plug it in there. Then disconnect (and optionally remove) the wire that goes to the coil from the ignition. In my experience it's been white, but in your case it looks to be orange. Either way, its the one "not from the starter".