One major problem with buying a rebuilt carb through a parts house is grouping. The rebuilder groups many different original carburetors together, and then builds to his own specifications. Then the rebuilder assigns his own part number to the new specification, and provides an interchange to his specification.
Sometimes the groupings are relatively decent. Sometimes they are not.
If the OP wants a Carter, then here is a suggestion: take a look through the archives on this forum. I have listed each of the Carter YF carbs that work on various Chevrolet 6 cylinder engines.
Find the specific carb (ebay is one source); obtain a rebuilding kit, and rebuild the carb yourself. It is not rocket science.
Jon.