Here’s the maintenance booklet for 1951 Rochester model B carburetors. When you have the air horn off check it against a flat surface for straightness. If the carb leaks or weeps people tend to tighten the air horn screws which in turn makes it warp/leak even more. At some point the air horn was redesigned to add more rigidity and if you ever purchase a rebuilt one (Autoline remanufactures these carbs) it will likely be the later design and have less likelihood of leaking.
