Michigan Motorsports Rod Bearings Rod Bearings, SI-Series, Standard Size, Bi-metal, Silicon Aluminum, Chevy 4.8 5.3 5.7 6.0 6.2 Gen 3/4 Set of 8 Michigan Motorsports SI-Series bearings are recommended for stock or performance engines using factory crankshafts. The bearings have an improved finish for reducing microscopic ferrite peaks on improperly ground or polished nodular cast iron crankshafts. SI-Series bearings feature improved oil clearance to reduce wear and increase engine life, which in turn reduces operating noise, vibration, and excess oil flow.