Quote:

Do NOT block it off...that's your atmospheric vent to the bowl. If anything, just leave it as it is.




Yup, just leave it open. Won't hurt a thing.
Best thing you could do is eliminate it (2BBL) with the manifold. What I mean is, take the 2BBL manifold off, and put a 4BBL on it. I did with my 360, loved it. Never looked back.