Forgot to mention that your lighting system (both running lights and headlights) will benefit greatly from the addition of modern relays in the circuitry. You can wire in your own relays, or purchase pre-fab kits from Dave Irwin (https://www.datsun-240z-upgrades.net/) or MSA Auto.
Benefits include better current flow to the bulbs (directly from the alt/battery), and less amps flowing through the 50 year-old combo switch. These upgrades are particularly important if you're still running old-style bulbs and sealed beams, but they make sense also for anyone that's upgraded (e.g. LEDs, etc).