You are in luck THIS year by my calcualtions.
As I understand the Cali law they made (up to) 1973 exempt about five years ago and then determined that any car 30 years old or older would be/become smog exempt as the years pass ... that meaning there was no change until this year and from here on out every year all cars 30 years old will BECOME exempt.
This (being 2004) your 1974 BECOMES smog exempt.
Check with your department of motor vehicles ... they will have the facts for you
I lived in Cali for ten years but then I've been gone for forteen ... so what the helk do I know