Clevite MS-1266A Engine Crankshaft Main Bearing Set Manufactured from cast copper-lead, increases fatigue strength by approximately 20% compared to powdered metal processes, referred to as sintering, which is used by the competition Relatively harder aluminum alloy wears well, interacts closely with journal surfaces for strength Recommended for use with nodular iron crankshafts Manufactured with 100% bored inside diameters for optimum surface characteristics and consistent precision Manufactured to meet or exceed OE specifications