One more time- - - - - -
YOU DO NOT NEED AN EXTERNAL REGULATOR WHEN USING AN ALTERNATOR.
Run the big output wire from the alternator straight to the downstream side of the ammeter. Connect all the supply wires to such things as the ignition switch, headlights, and any accessory fuse block(s) to the same terminal. The only thing that gets attached to the other side of the ammeter is a single heavy wire (#8 maybe) to the battery cable terminal at the starter. Do not connect ANY wires to the original 3-unit regulator. It's not needed. You can remove it, and the wires attached to it unless you plan to go back to a generator/regulator setup sometime in the future.
Jerry