Clevite MS-909H-30 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 H-Series bearings are narrowed for greater crankshaft fillet clearance All H-Series bearings are made in Atlantic, Iowa USA High crush for better seating and retention Un-plated hardened steel backing for better dimensional accuracy and bore contact