King Engine Bearings MB555HP High-Performance Main Bearing Set Chrysler Big Block

The King Engine Bearings MB555HP is a high-performance main bearing set engineered for Chrysler big block engines including 350, 361, 383, and 403 cubic inch displacements. This bearing set is part of King's HP Series racing line, designed specifically for demanding performance and racing applications.

Alecular Bearing Material Technology:

These bearings feature King's proprietary Alecular bi-metal construction, consisting of an aluminum alloy top layer strengthened with 2.5-3% silicon bonded to a high-strength steel backing. The thick .012-.015 inch Alecular layer provides superior embedability and can withstand wear up to .010 inches without damaging crankshaft journals. This advanced material offers a Vickers hardness rating of 40, making it harder than traditional Babbitt materials and ideal for resisting surface migration and extrusion under extreme loads.

Performance Features:

• Bi-metal construction with aluminum-silicon alloy for exceptional durability
• Optimized for medium to high-load engines and nodular cast iron crankshafts
• Superior resistance to high loads and metal-to-metal contact during short duration events
• Enhanced embedability for improved protection against contaminants
• Temperature threshold nearly 30% greater than tri-metal bearings (450°F vs 350°F)
• Features King's Bull's Eye Tolerance™ Technology for precise tolerances

Applications:

Ideal for street/strip performance builds, blown engines, turbocharged applications, and racing applications using aftermarket or nodular cast iron crankshafts. Commonly used in classic Mopar muscle cars including Dodge Charger, Challenger, Plymouth Road Runner, and Chrysler 300 models equipped with these big block engines.

What's Included:

Complete main bearing set with all necessary bearings for one engine rebuild. Set includes upper and lower main bearings with half-groove configuration for improved oil distribution at high RPM.