Datecode example: 0650 065=day of the year 0=year (1970,1980) Carburetor number example: 7040502 70=GM carb prefix, later carbs used 170 instead of 70. 40=1970,41='71,42='72,43=73,44='74,45='75,46='76,47='77,48='78,49='79 80='80,81='81 5=California or High altitude emissions, 2=49 state emissions. 0&1&2=Chevy, 3=Cadillac, 4=Buick, 5=Olds, 6&7=Pontiac. 2=transmission type (even numbers are automatic, odd numbers manual trans) (NOTE:Some Quadrajets are made by Carter instead of Rochester. This likely occurred when Rochester was unable to keep up with production. Carter QJs decode the same as Rochester using this method.)
