The smallest one I show is a 1-1/16" venturi.
I guesstimate its flow at about 96cfm at 1.5" Hg (the 4bbl rating), the perfect size to feed about 60hp.
Yup its tiny.
I did a carb shootout with a bunch of these carbs:
1-1/16" venturi ~96cfm
1-11/32" venturi ~140cfm (the most common car 194 and 230 carb)
1-9/16" venturi ~185cfm (mainly 292 trucks but also the 250cid and the 230HiPerf)
The 250cid and 292cid launched just as well with the big jug as it did with the medium size carb if the carbs were set up right.
That little 1-1/16 job (I only have one) ran like a sick dog, WAY too lean until I punched out the power valve hole. Even when I got the mix right, it was just way too small, I had to guesstimate the airflow at 96cfm to match what the GTECH was telling me. Even two of them is only the same size as a single Big Jug "B" carb, which is still too small for almost any six.
If you plan 2 carbs you might try a pair of the more common 1-11/32" venturi, they are dirt cheap at swap meets.
What is your engine build?
