On an EFi turbo (ERST or FRST): One large port to the rocker cover, one large port to the airbox and the small port to a tee piece that joins the two inlet manifold vacuum ports together. The small vacuum must be there for EFi to idle correctly.

Edit: I used one from an MFi ERST, its smaller and more readily available. I didn't connect my breather pot to the airbox, just vented the pot to atmosphere.

Lee