Hey Guy's, There are a number of 522 pulleys on ebay that say orginal. Some have the 522 part number and the S at bottom but some have AO at the end of the 522 part number. I know the repo doesn't have the S on it but Why does some of these so called orginals have the AO at the end of the part number and some don't. If I am going to spend this kind of money I want the correct one. How do I make sure to buy an orginal assembly line 522 pully. Any low mileage orginals with pully that can give me some onfo. Thanks Gary