Rochester identified their carbs with a foil tag attached to the top with one of the hold down screws. Very easily ripped or forgotten after a rebuild.
Some of the carbs were stamped in addition to the tag on the underside of the carb. I got lucky and mine was stamped. Its the four digit number on the right.
Good Luck!
Phil Moderator, The Engine Shop, Interiors and Project Journals
1952 Chevrolet 3100, Three on the Tree, 4:11 torque tube Updated to: ‘59 235 w/hydraulic lifters, 12v w/alternator, HEI, PCV and Power front Disc Brakes Project Journals Stovebolt Gallery Forum