Jon's comment about basically similar-appearing carburetors having widely different calibrations is something I learned while going to GM training schools on Quadrajets in the late 60's, 70's, and 80's- - - - -There were something over 200 different QJ part numbers over a 20+ year production run, calibrated for everything from a 230 cubic inch Pontiac OHC 6 cylinder to a 500 Cadillac engine. They all look very similar to the untrained eye of a salvage yard scavenger!
Jerry
