I can tell you my experiences with CA smog testing; in 2002 I bought my 88 C1500 Silverado 5.7L from a guy who managed a transmission shop in Los Banos (San Joaquin valley). He had recently installed a GM Goodwrench long block and rebuilt the trans. When I bought it I had to get it smogged - no problems, each successive time - no problems. When I moved to AZ in 2008 I had it "emissions" tested - no problems every 2 years since - no problems. Just throw some dirt and oil all over the engine to make it look old and don't offer any information.