Hemi intake question

Can anyone tell me what the threaded hole in this manifold is for? In my old manifold there is a tube bent at almost 90 degrees; looks like it may have had a hose on it at some point. I've searched on line and in my service manual. Can it just be plugged like I've seen on some manifolds? I'm showing my inexperience here, but I can't figure out what it is. Thanks.

 

There's one like that on the Desoto 2x4 that I'm putting together for display. I got a br*** plug for mine.

 

manifold vacuum?

 

Power brakes

 

looks like a good spot to hook up a valley cover pvc valve.

 

Its a vacuum port for the power brake booster.

 

Thanks very much. I appreciate the responses. Well the next car definitely wont have power brakes, so I'll plug it. You guys never let me down.