Quote Originally Posted by canadianal
.... did gm make 2 sizes of bores in a quadrajet??
Hey Canadi or do people call you anal for short? Sorry, I couldn't resist. I tried deleting it after I read it but for some reason my back space isn't working, hopefully your back space is.
Yes, there are two sizes of Quads in bore sizes and even more sizes via spring and needle adjustments.

If memory serves me right, there is a 750 and a 850 cfm. The difference is in the front two ventury bore sizes. If you have the two carbs next to each other, it is easy to tell them apart due to the shoulder size inside the venturies. The back space remians the same.
Yours truly, Bob