Stock Intake Manifold

Hi misters,

well excuse me for the disturb but i have a doubt with my intake , effectively its a stock intake in 2bbl and i see two hole in the drain .

There is a big hole with a threading and a other hole next without threading , and my question i do block the two hole or not and how ?

For the big hole ok i doing a screw but for the small hole without threading how ?

Coordialy , Tof