cleaner air package

Was a California smog tech ,'88 to 92... Nox ,was,the biggest issue. Allowed unlimited timing retard ,installing those wonderful " Nox retrofit systems ".... That would be buy it from a supplier, for 4 to 6 bucks , marking it up 200 -250 percentage, and install a sticker on the windshield, installing two vacuum nipples in place ,of the factory vacuum advance line. Those years with carburetor applications,...were interesting.