1973 Chevy vs Oldsmobile main air bleeds

[Glutenfreecarbs]

I saw some discussion of different divisions' MAB sizing the other day, and happened to have both a 7043208 (Chevy) and 7043251 (Olds) on the bench, so I took these photos...

[73ss]

why did the different divisions do this? Assuming both carbs are from a standard smogger engine from '73.

[Cliff Ruggles]

Quadrajets are application specific.  Each one is set up exactly for the engine it ended up on.

Even if you are working with a Chevy large MAB unit take a look sometime at the wide variety of jets and metering rods they used in each one depending on the engine.

You will also see different MAB sizes within the same divisions, like the Buick 350 and 455 carbs.  They are set up completely different even in the same year of production.  Compare a 1971 350 Buick carb sometime to a 455 the same year......