Rochester Carburetor CFM


Rochester Quadra-Jet carburetors only came in two cfm ratings, 750 and 800. The difference is in the primary venturis. In the image, the left has the small 1-3/32-inch used in the 750 cfm carburetor. In the right, there is the larger 1-7/32-inch venturi found in the 800 cfm carburetor.

You want to notice the ring in the outer venturi, the one on the left is thicker, the one on the right thinner and shows a bulge in the 8 o'clock position in this photo.
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