This is the reason I left that piece of crap, but beautiful State. The Commies have ruined it. Born and raised in So. Cal. Always built my own small blocks since high school. Couldn't get them registered by the 90's, even though the Smog shops said they passed emissions, but the "new visual" rules failed. Hell, I wasn't going to put cat's, egr's, air injection, electronic quadrajets, on my clean street cars.
So the Mexicans at a couple of smog shops in O.C. said they could pass it for a C-note or two. That went on for a few years. Then they said I look like a cop and wouldn't do it anymore. Then I found a couple of Vietnamese smog shops that would do it for $3-$400 to pass my 77 El Camino and my 82 Camero. Then a couple of years later I could only find one shop that would pass it for $600 each, did that for a few years. Then it was over as CA made it a felony for a smog shop to cheat.
That was it. Time to move or sell my rods. About the same time, they were doing the "Assault weapons" b.s. Going to make a felon out of me with the stroke of a pen. I packed up my crap, my Woman, and left with $6,000 in my pocket. Took 3 trips to move to AZ, where only Phoenix and Tucson have smog. I moved to Lake Havasu with no smog checks, could take my built lake boat out every weekend, and be free. Got older, got tired of the heat and the $500 a month Air conditioning bill, and moved to Utah. Still Free to do and own what I want...for now.
Don't get me wrong, I don't dump my used oil in the back yard, and my cars and trucks with no emissions put out less pollutants than most of the idiots with newer cars driving around with seven codes behind their check engine lights.
I would gather ALL the stock components you can find at salvage yards, it's a pain in the rear. But every smog cycle you will have to spend a week putting all the smog crap on, tuning it the best it can do, pass the test, and spend another week taking it all off, and make it run sweet again. After a while you will have it down to few hours on a weekend.
There are tons of CARB compliant stuff you can do, and newer OBD2 cars and trucks have it much easier as you can put a scan tool on it and know if you will pass before you go in. But for older vehicles its a coin toss, and a coin drain in your wallet and labor.
Your going to spend hours doing research, it's all our here somewhere, just got to find it. And may the chains of Tyranny lie gently upon your feet.