Arizona emissions testing

When I had my 71, they just have to be ran on the sniffer. They never actually looked for the emissions stuff. They just check the gas cap to see if it seals (they look at the rubber seal), and then run it on the dyno and measure emissions at cruise (35 mph) and then idle. If the engine is a fresh rebuild, then the emissions should be good. They test for Hydrocarbons (HC less than 380 PPM) and Carbon Monoxide (CO percentage less than 5%). A well constructed rebuild should blow clean, as long as the carb is adjusted right.

My 71 duster had a 408 stroker and blew clean every year.