carb difference

[firedan]

i have two quad jet one is original and to my 78trans am W-72 400 auto with the numbers 17058266 and the other is 17058278 i know both are from 78 cars and automatics but what else is different. thank you

[Cliff Ruggles]

Very little difference, same castings, throttle body, airhorn, etc.  Might be a vacuum fitting or two that aren't the same, and slightly different calibration, that would be about it.....Cliff