You need to have the appropriate flange welded to your charge piping. You match the flange type(aluminum or steel) to your piping type. You also match the flange type to your BOV, since different manufacturers use different style flanges. Once the flange is welded up, you install the BOV to the flange, and connect its vacuum nipple to manifold pressure. You can tee off any vacuum line that comes off the manifold.