I think I know the answer just need confirmation.

I am trying to install my AEM intake. I have a 3 port and not the stock BCS can I just cap one of the vacuum lines.

Thanks in advance.

 

No, route it back into the intake.

 

Thanks kracker for the response. My explanation may have been poor.
I have the AEM intake which has 2 vacuum lines. Instead of the one like on the factory inlet tube. I want to/did cap off the second line and ran the 3 port line back to the intake. I was never intending to cap off the line coming off the 3 port.