This is a used carburetor core in need of cleaning, rebuilding, and for purposes of restoration and or parts.
Not presumed to be running carburetor.
This is a Autolite 2100 carb with 1.14 venturi, the number decoded is C6DF-B, see pictures. From a 1966 Ford Mustang but also interchanges with Mercury Cougar and Ford Fairlane with a 289 engine