Fallout: New California adds an all new story around a new player character, an adopted resident of Vault 18, embarking on a journey through the wastelands of the New California Republic's Cajon Pass. An unofficial prequel to New Vegas, FPB adds hours of new gameplay and a fully voiced stand alone campaign.
The guide on how to Install New California correctly!
You absolutely need 8GB of RAM.
You absolutely need the 4GB Patch: Nexusmods.com?
You must install MO2 & Vortex mods on the same hard drive as New Vegas.
More tips and tricks for better performance: Youtube.com
Thanks to Gamer Poets for the Videos!