Intake Manifold top hole

[Stryker7314]

What is everyone using to plug the top hole of the aluminum intake manifold?

 

[Wayne clark]

I would think some type fitting for connecting a vaccumn source to .

 

[drag-200stang]

Do not use that location for PCV, it will lean out #6.
I would use an aluminum plug, But I do not know what size.

 

[sixtseventwo4d]

Better to use a brass plug