Here are some links to assist you with registering your Historical truck in California. The Southern California Chapter of the American Truck Historical Society and the American Truck Historical Society assumes no liability in how this legal information is used and/or interpreted. This is for informational purposes only and is intended to clear up any misinformation you may have heard.
This doc shows Historical Vehicle Parameters:
Link: Law section (ca.gov)
This doc shows CARB exemptions....2025 (C-9) (D-36):
Link: Truck & Bus Regulation Language (ca.gov)
DMV link to special plates:
Link: Special License Plates - California DMV
Actual application for Historical Vehicle Plates:
Link: REG 17 A, Special Recognition License Plate Application
You should start with a clear title in Non-Op status in your name. If you don't have one, get one before using this information. If the truck has been registered with CARB, the registration with DMV may be on hold. You will need to use these documents to clear this through CARB first. Please read the form carefully before sending it, send it to the address at the bottom of page 1(this bypasses those ignorant of our cause), include your title (because it is a commercial vehicle as of now), the completed forms, and $25. They will send back a request for whatever information they are missing along with a bill for the new registration (around $100). Send it back completed and they should send you a new Historical Automobile title and plates. This process may take 60 days or longer.