These King SI-Series main bearings are recommended for OE applications. These main bearings are designed for aftermarket gasoline or diesel engine rebuilding and performance engines with OE crankshafts. These King SI-Series main bearings have an improved crankshaft finish for reducing microscopic ferrite peaks on improperly ground or polished nodular cast iron crankshafts. These 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.
