The thing with Pep Boys is the same as any shop....you have to know the managers and quality of the mechanics. There happened to be one such Pep Boys near me that was managed by a guy that raced both cars and boats. Would always know exactly what you wanted and would mother hen the installations with the mechanic(s). Never had a problem. You can always pay double or triple at a dealer if that makes you happy. The most respected rearend shop in my area charges $325 for a ring and pinion gear change....Ford will charge you almost $1,500! Do what floats your boat.