I have just been through the California Smog Certification process (again) with my 1979 F250 460ci. 4x4. With the experience of dealing with many smog stations including a trip to the referee station, all smog emmissions equipment is required to be installed except the charchol canister and the hot air pre-heat for the intake.

Also, from the early '90s to the present all conversions need to be CARB approved and certified. A small technicality for california conversions!