Classic/Antique Car Repair: vacuum wipers connection, vacuum booster, manifold vacuum

Question
1954 GMC truck, I have a fuel pump with vacuum with two openings that are wide.  How to connect this pump to vacuum wipers.  Is this used in conjunction with the manifold vacuum using a T-type connection?  What to do with the other opening on the fuel pump, plug-it or leave it open?

Answer
This pump is a vacuum booster pump that will provide vacuum to the wipers when the engine is under heavy load like climbing a hill. Gas engine provide very little vacuum under load so the booster pump is necessary to ensure wiper operation. With the engine running at an idle put your finder over one of the outlets. If it has vacuum then that is the one that connects to the wipers. If it has pressure that is the one that connects to he intake manifold right below the carburetor. I would prefer that it be connected directly to the manifold with no "T" depending on what the other vacuum line is for. But the wiper connect to the pump with no "T" or other vacuum device running from the pump.