This is a Tillotson  refurbished carburetor sold and used on the Model A Ford cars for many years. This is a replacement to the Zenith carburetor. These carburetors are a better running carburetor then the zeneth. carburetors. Ask people who use them.  I have been rebuilding these carburetors for over 55 years. My ebay score is at 100% satisfaction. I soak them in carb. cleaner for a few days to remove all old gas and grime. Bead blast comes next, replace and size all jets, replace with a new needle and seat, and assemble with new gaskets. This will give you many trouble free driving miles.  If you have any questions, please contact me. I am always looking for good old carburetors working or not to buy or trade.  Thanks for looking.