King Engine Bearings MB557GPC020 GPC Race Main Bearing Set 0.020 Undersize

The King Engine Bearings MB557GPC020 is a GPC Series race main bearing set engineered for General Motors small-block engines including the 262, 267, 302, 307, 327, and 350 cubic inch V8 platforms. This set is ground to 0.020" (0.50mm) undersize, making it the correct choice for engines with a reground crankshaft at the standard 0.020" re-grind specification.

GPC Technology — Built for Extreme Load Applications:

• Silver-based tri-metal construction — features a lead-free silver overlay containing solid lubricant additives distributed throughout the silver matrix for outstanding load capacity
• 17,000 PSI load capacity — handles over 54% more load than conventional race materials that peak at 11,000 PSI
• 30% stronger than standard tri-metal race bearings, making them ideal for highly modified, forced-induction, and extreme-duty race engines
• Polymer coating — in-house developed top coating provides low friction, high wear resistance, and critical protection during oil starvation and metal-to-metal contact events
• Lead-free formulation — environmentally responsible construction without sacrificing performance
• No added wall thickness — factory-applied polymer coating maintains original precision wall thickness dimensions for accurate oil clearance

The four-layer GPC structure consists of a steel backing, a lead-free bronze intermediate layer with added tin, a silver-based overlay, and a top polymer coating containing solid lubricant and ceramic additives. This advanced construction is engineered to handle the on-and-off loading, extreme cylinder pressures, and high RPM demands of circle track, sprint car, drag racing, and other high-load motorsport applications.

Specifications:

• Material: GPC Silver-Based Tri-Metal (Lead-Free), Polymer Coated
• Undersize: 0.020" (0.50mm)
• Application: GM Small Block V8 — 262, 267, 302, 307, 327, 350 cubic inch
• Max Load Capacity: 17,000 PSI
• Country of Origin: Israel