King Engine Bearings MB5224AM AM-Series Main Bearing Set GM 400ci 6.6L V8 OHV

The King Engine Bearings MB5224AM is an OE-replacement main bearing set designed for the General Motors 400ci (6.6L) V8 OHV engine. Part of King's AM Series, this set includes 5 pairs of bi-metal crankshaft main bearings engineered to deliver reliable, long-lasting performance in street and marine applications.

King's AM Series uses a standard aluminum-based material equivalent to SAE-783 — the softest bi-metal in King's lineup — making it ideally suited for passenger car and light-duty engines operating under low to medium loads. These bearings are also completely lead-free, prioritizing environmental safety without sacrificing performance.

Key Features:

• AM Series Bi-Metal Construction — Aluminum-based material (SAE-783 equivalent) optimized for low to medium load applications
• Lead-Free Formula — Environmentally friendly and user-safe material composition
• Bull's Eye Tolerance™ Technology — Precision wall thickness control to within ±0.0001", combining accurate machining, overplating, and computerized monitoring
• Superior Embeddability — Allows macro-particles to embed into the bearing surface, reducing crank journal scratching and overlay wear
• Half-Grooved Mains — Upper shells are grooved for optimized oil distribution while preserving lower shell load capacity
• Sold as a Complete Set — Includes 5 pairs (10 shells) for a full main bearing replacement
• Spacer Application — Compatible for use as a spacer set when installing a Chevrolet 350 crankshaft in a 400 small block (use with MB557SI main bearings)

Cross-reference: Clevite MS1564P. King Engine Bearings has been producing precision bearings since 1960 for automotive, marine, aviation, and performance applications worldwide.