These are RARE NOS small base Rochester Marine Carbs. These work excellent for custom tripower set ups or single use. 
 
These carbs have the correct 1.250* Venturi
(the largest cfm venturi in the small base family)
 
Correct Jetting
Correct True Tripower Base Plate
Correct Mixture Screws
Correct Front Fuel Inlet Air Hom
Correct Hot Air Choke Housing
Correct Choke Stat Cover
Correct - Blueprinted - Automotive Main Metering Cluster
 
These are easily cloned into 
 
1959 - 65 Pontiac Tripower Center Carburetor 
1957 - 58 Pontiac Tripower All Positions
1959 - 60 Cadillac Center Carburetor
1957 - 58 J2 Olds All Positions 
1958 Chevrolet 348 Tripower All Positions 
 
These carbs have been sitting in storage since 1966. They will need to be taken apart, cleaned, rebuilt and or restored. The great thing about these carbs is your starting off with a brand new never used or altered carburetor.