King Engine Bearings MB557GPCSTDX GPC Silver-Based Tri-Metal Main Bearing Set

The King Engine Bearings MB557GPCSTDX is a GPC Series main bearing set engineered for extreme-load racing applications in General Motors small block engines, including the 262, 267, 302, 307, 327, and 350 cubic inch displacements. Built to standard size with extra clearance (STDX), this set is purpose-built for high-performance and race engine builds where conventional bearings fall short.

GPC Series Technology:

• Tri-metal, silver-based overlay construction — a lead-free silver matrix engineered specifically for extreme load race applications
• Solid lubricant additives distributed throughout the silver overlay matrix for enhanced protection during oil starvation and high-stress events
• Coated bearing surfaces for improved break-in performance and reduced initial wear
• Lead-free formulation meeting modern environmental and performance standards
• Standard size with extra clearance (STDX) for use with aftermarket or blueprinted crankshafts requiring tighter oil clearance control

King Engine Bearings' GPC series combines a unique tri-metal structure with advanced surface processes to handle the extreme cylinder pressures and loads found in purpose-built race engines. Sold as a complete main bearing set.