If it idles smooth with 16 in. of vacuum I don't think it's a vacuum leak. Do a fuel pump volumn check. Disconnect the line from the carb & put a cup under it. Start the engine . It should fill the cup in 20-30 seconds. What about the filter inside the fuel inlet fitting? If you give me the carb # I can get the specks on it tomorrow. Usually the float level is 1/4 in below the top of the bowl to the top of the float. With the throttle closed push down on the metering rod holder. It should be 2to 3/32. from the top of the bowl.The metering rod spring should be on top of the holder. Some oddball aftermarket needle seats have a tiny screen in them. I just had one of those throw me recently.
