This is the manifold that originally came with a Zenith S4BF when you bought one brand new back in the day. These are as common as hens teeth. This one is in perfect condition, has not been ground out the way many of them were, and has not been drilled for a vacuum line. If you have one of these carbs this offsets the carb towards the back of the car so that it will clear your generator or high tension magneto. Selling this now because I sold my two S4BFs as a pair. Asking $250 plus shipping.