After posting the diagram above I noticed that it was the one that shows how to convert to the internal regulator alternator by jumping the wires in the external regulator plug. All that's needed is an adapter plug for the SI alternator,which is about $5.00 at the auto parts store. No resistor is needed for this conversion and running the blue wire to the no. 2 terminal on the alternator will reduce any voltage drop on the circuit.
With a one-wire alternator, the blue and white wires would not be used and only the large red wire from the back of the alternator needs to be run to the main junction.
Here is how I convert the alternators. It is much cleaner and eliminates the external voltage regulator plug and it's wiring.
Simply run the brown wire from the firewall connector to the no. 1 terminal on the new alternator and run the red wire from the junction to the no. 2 terminal on the alternator. Then upgrade the 12 gauge wire on the back of the alternator to 10 or 8 gauge and run it to the main junction.