There are other Rochester posts kicking around right now and it is hard to recall what I've posted and when. Size of fuel inlet valve (some call it the seat) is very important. Look below at the 3 different sizes I found in 5 Rochester B and BC carburetors. Compare please the smallest to the largest. It is sort of like a horse needle compared to the needle used for a flu vaccine. Carter knew very well the implications of the size differences. I'm not certain about Rochester. Honestly I've said it here before but I think whoever designed the B and all variants was the son or grandson of some GM exec that flunked out of engineering school and needed a job.
I wouldn't rebuild these either. For one thing it is almost impossible to find one that didn't go through the commercial rebuilder's mixmaster and therefore you have no idea what sort of Heinz 57 carburetor you have now.
~ Jon 1952 1/2 ton with 1959 235 | T5 with 3.07 rear end
