More Holley questions 1850

Im rebuilding my 2 1850 600 CFM carbs. Everything seems to be going back together with no issues but I found one thing Im not sure about. Now I bought these 2 carbs used so Ive never run them but during the rebuild I noticed that there is an open vacuum port that goes from the side of the carb to the center of the base. Im guessing there is no vacuum there but thought I would ask if i need to plug it. Take a look at the pics and let me know what you think. Also I have taken a pic of the float in the bowl. this is also the first holley Ive had that doesnt have an external adjustable needle and seat. I set the float level with the top of the float. Will this be to high? The paper work instructions didnt have a measurement to set it for my number and many of the setting says level with top so thats what i did.
Thanks for your thoughts in advance!
Rod
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