I don't remember the last year but into the 1980's.
In approx 1977 I bought a 57 Pontiac and had to install the temp controlled vacuum advance to register it even though it didn't require semi-annual smog checks. Retro ones you cut the top radiator hose in installed this temp controlled valve, I just bent the hose and attached it at the end, the smog tech laughed. Had to remove the old style crankcase vent also, those were a 1inch metal tube that entered the engine near the distributor and snaked down to just below the bellhousing.
My F250 has valve cover breathers with rubber hoses that snake down to below the engine and dump the fumes there.
I bought the wife a garden tiller about 5 years ago - CA only model. It ran fine then after about 40 hrs started quitting on me. Turns out the CA special has a rubber hose as a crankcase breather that feeds into the air cleaner and those small engines can't adjust for even a small change in air/fuel mixture. Took the hose out of the air cleaner and it runs fine. Fuck CARB and the AQMD.
When they find a way to stop China's air pollution from coming here on the natural wind currants then I will consider playing by the rules.