When you convert from the external regulator alternator, you no longer need the regulator that is mounted on the radiator support. You also don't need some of the wiring that is present in the loom.
The diagram below shows the original connection at the old regulator. (I'm sorry, but the wire that is colored yellow, is really white)
The next diagram shows how you modify the loom at this location.
Notice that the blue wire is jumpered to the brown wire. The white wire and the orange wire are just capped off so that they will not short out to anything.
This next diagram shows what you have to do at the new alternator.
The wire that goes from the "BATT" terminal to the #2 terminal is a new wire that you will have to add. You can use a 14 gauge wire.
The white wire (shown yellow) just gets capped off.
You will need a new connector to fit the new alternator and they can be purchased at almost any auto parts shop.
Due to my being bothered by the "extra" wire being in the loom, I totally removed the dead white and orange wires. I also wired the brown wire to the alternator directly. It just gets rid of some extra length of wire.
The prior paragraph has caused me a lot of e-mail feed back and hopefully the following information will clear it up. In my final wiring configuration, the "brown wire" comes from the alternator indicator light, through the firewall connector, and directly to the alternator. The result is electrically the same as the diagram at the top of the sheet, just cleaner. The diagram above would have the brown wire coming out of the connector at the firewall, going toward where the regulator was, connecting to the blue wire, then the blue wire goes to the alternator. As I said, I cleaned up the wiring (and in the process, dirtied up the wording).
In order to ensure good connections, I recommend that you always solder the connections and then use heat shrink tubing to seal it.