Just replaced the old belt on the Mustang with a brand new one and, of course, the squealing didn’t go away. The odd thing is the squealing will go away if I take a damp cloth and touch it to the ribbed side of the belt. Thinking it was dirt or grime in the grooves of one of the pullies I then took some WD40 and a stiff-bristle brush and, with the belt removed, scrubbed every single pulley including the crank pulley. Put the belt on and the DAMN THING STILL SQUEALS AND MY EARS ARE BEGGING FOR THE SWEET RELEASE OF DEATH. My only thought is that the brand-new expensive fucking belt I got from O’reilly and no longer have the receipt for (of course) was sitting on the shelf for so long the rubber has gone to shit.