Stop in for a cup of coffee

Where am i going to find a 2 groove alternator pulley? I had a collection, and at one point i could order but that supplier had gone by the wayside.
Belt is tight like e-flat piano wire and its squeals when i start truck. Thinking dual pulley is the answer, and i could back off tension a smidge,to take pressure off water pump and alternator bearings.
or something is dragging????