That is supposed to be a 9.5 wide belt in there. Who ever sold you that belt gave you the wrong one. Almost everyone does it. The result is that it will need to be overtightened to stop squealing, hence broken alternator mounts and blown bearings in the pump and alt. Now they get to sell you a new improved mount and new alt and waterpump. Make the effort to get the right size belt. Just because most people sell you a wrong belt does not change the size of the pulleys on your engine.
rant over
mike