Intake Oil Filler---Block Off

[ktownkid]

Hello,
Well, I finally found a C3BX intake that I liked, though it is dirty. My question is, I want to block off the oil filler tube location at the front of the intake. Everyone says to use a freeze plug. Do you have to use some kind of gasket to prevent oil or air leaks???

I have also heard a freeze plug is the wrong thing to use, but what would you use if not a plug???

Thanks----
ktownkid