Tubo bypass valve

Hey everyone, Im from Australia. Had my '85 Saab 900 Turbo for about a year now, and im looking to fit a blow off or bypass valve, as the turbo has just been reconditioned. I was wondering if anybody knows where i would find an appropriate vacuum source for the application of one? Ive attached some pics if that helps






Also, does anybody know what this is, or was for?


Any help at all would be greatly appreciated,
Thanks heaps

any vacuum source behind the throttle body will provide proper vacuum to open the BOV.