Fuel mixture

[Colin]

Just bought a 1984 Eddie Bower with 60,000 original miles but it is running VERY rich and uses gas like my 351M in my old 1978 XLT Ranger 4x4 truck. It will not pass a smog as yet and the techo at the station does not know what to do!! Could it be the oxygen sensor? He has adjusted the carby for mixture and idle speed and seemed to get that pretty good, but the exhaust still smells awfully rich when running.