KING MAIN BEARINGS .020 SBC

King SI-Series Main Bearings MB 557SI 020

Main Bearings, 1/2 Groove, .020 in. Crankshaft Undersize, Bi-metal, Silicon Aluminum, Chevy, Small Block, Set of 5

King SI-Series main bearings are recommended for OE applications. These replacement bearings are designed for aftermarket gasoline or diesel engine rebuilding—and performance engines with factory crankshafts. The bearings have an improved crankshaft finish for reducing microscopic ferrite peaks on improperly ground or polished nodular cast iron crankshafts. King SI-Series main bearings feature improved oil clearance to reduce wear and increase engine life, which in turn reduces operating noise, vibration, and excess oil flow. Order the bearing set designed for fitment on your make and model.