King Engine Bearings MB556SI060 SI-Series Main Bearing Set Big Block Chevy 396-502 Gen IV/V/VI 0.060 Undersize

The King Engine Bearings MB556SI060 is a complete SI-Series crankshaft main bearing set engineered for Chevrolet Big Block 396–502 cubic inch engines across Generation IV, V, and VI configurations. This set is the 0.060-inch undersize variant, designed for use during engine rebuilds where the crankshaft journals have been machined beyond standard dimensions.

Built using King's proven bi-metal silicon aluminum construction, the SI Series bearing material uses an aluminum base alloy strengthened with 2.5–3% silicon. This formulation is specifically suited for medium-load engines and nodular cast iron crankshafts, delivering reliable wear resistance and consistent oil film retention throughout the bearing's service life.

Key Features:

• SI-Series bi-metal construction — aluminum base alloy with 2.5–3% silicon for durability under medium load
• 0.060-inch (0.60mm) crankshaft undersize — for use on reground or machined crankshaft journals
• Half-groove design — improves oil distribution across the main journal surface
• Improved oil clearance — reduces wear, lowers operating noise and vibration, and controls excess oil flow
• Compatible with nodular cast iron crankshafts — ideal for OE-style engine rebuilds and restorations
• Application-specific engineering — King tailors bearing geometry and material to the demands of each specific engine family

King Engine Bearings has specialized exclusively in engine bearings since 1960, providing OE-quality solutions for gasoline and diesel engine rebuilding. The MB556SI060 is the correct choice for Big Block Chevy rebuilds requiring a 0.060-inch undersize main bearing with proven bi-metal SI-Series durability.