questions bout my greddy BOV

it has two different size ports where you connect up hoes to. i know the top bigger port is for the vaccum on the intake ports,but what is the other smaller port for? does my boost gauge hose connect to this?

The lower port (in the valve body) should be connected to your intake tract before the throttlebody. That way when there is pressure in the intake tract and vacuum in the intake manifold the BOV will lift. If you hook your Boost Gauge to the lower port it will never read anything... You can T off the line going to the manifold port on the BOV though.

okay thanks