King Engine Bearings MB555AM AM-Series Main Bearing Set Standard Size Bimetal

The King Engine Bearings MB555AM is a standard-size AM-Series crankshaft main bearing set designed for Chrysler big block B-series engines displacing 350, 361, 383, and 403 cubic inches. This bimetal set uses an aluminum-silicon base material (equivalent to SAE-783) ideally suited for street and marine applications operating under low to medium engine loads.

Key Features:

• AM-Series bimetal construction — aluminum base material equivalent to SAE-783, optimized for low and medium load applications
• Full groove upper bearing — half-groove design ensures consistent oil distribution to crankshaft journals
• Superior embeddability — effectively traps macro-particles to reduce crank journal scratching and protect bearing overlays
• Bull's Eye Tolerance™ Technology — combines precision machining, overplating, and computerized wall thickness monitoring for tolerances held to within ±0.0001 inches
• Lead-free construction — environmentally friendly and user-safe formulation
• Standard (STD) crankshaft undersize — direct replacement for unground factory crankshafts

King Engine Bearings has been a specialist in high-performance and aftermarket engine bearings since 1960, supplying demanding industries including aviation and motorsport. The MB555AM brings that same engineering expertise to Chrysler big block rebuilds, delivering reliable crank support for street drivers and marine enthusiasts alike.

UPC: 611500284106