Walt and Group, Let me correct my self. #1. The Black seal bearing made in China are your standard run of the mill bearings. Who knows how long they will last. #2. The EMQ Bearing ( Electrical Equiptment Quality ) This is the best, Made in Tiwan soon to be made in China, Best metal, Best grease and used in the alternators. You can normally tell them by the Orange,Blue or brown seal. Normally the brown seal is the extra wide bearing used in some limited applications. The color will vary by supplier. These do cost a little more and might be harder to find, but will last. #3. An application of the black seal bearing is used as the pilot bearing in the clutch. This would be an application of limited usage compared to the treatment of the pulleys on the alternator or the idler puleys. I will get some of the bearings and put them on the site for you to purchase or exchange. John Hervey www.specialTauto.com