The field stud of the alternator should be marked FLD or F, and this goes to the F terminal of the voltage regulator. The stator terminal of the alternator should be marked STA or S. In your setup, this would go to the factory electric choke (if equipped - most aftermarket carbuertors call for 12-volts hot-in-RUN which is different). The S terminal of the voltage regulator is powered by hot-in-RUN from the cab, which I think is GREEN with a RED stripe; although you'd want to check with a wiring diagram.

The large output stud of the alternator should be marked B+ or something similar. This goes to two places - one heavy-gauge wire with a fusible link goes to the battery-side of the solenoid; another wire goes to the A terminal of the voltage regulator. The latter is the sense input to the regulator.

If your alternator has a ground stud (GND), you may connect it to one of the voltage regulator mounting bolts with a ring terminal. This helps keep both the alternator and regulator at the exact same ground potential, in case the two grounds shift over time (due to an aging ground strap, etc).

With your setup, the I terminal of the voltage regulator is not connected.