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King Engine Bearings

King AM-Series Main Bearings

4.24 out of 5 stars 33 Customer Reviews

King AM-Series main bearings are recommended for street or marine applications. These crankshaft bearings have superior embeddability, which provides greater macro-particle to reduce scratching of the crank journals and tearing or weakening of the Babbitt overlays. King AM-Series main bearings feature tolerance control to within plus or minus .0001—and they're lead-free, making them environmentally-friendly and user-safe. Hundreds of performance sets are available; order the replacement bearings designed to fit your vehicle.

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King AM-Series Main Bearings MB5278AM

King AM-Series Main Bearings MB5278AM

King AM-Series Main Bearings MB5278AM

Main Bearings, AM-Series, 3/4 Groove, Standard Size, Bi Metal, Ford, 2.3, 2.5L, Set of 5

Part Number: KGB-MB5278AM

3.0 out of 5 stars ( 1 )

Estimated Ship Date: Today

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King AM-Series Main Bearings MB5278AM0.25

King AM-Series Main Bearings MB5278AM0.25

King AM-Series Main Bearings MB5278AM0.25

Main Bearings, AM-Series, Alecular Silicon, 0.25mm Crankshaft Undersize, Ford, 2.3, 2.5L, Set of 5

Part Number: KGB-MB5278AM025

5.0 out of 5 stars ( 1 )

Estimated Ship Date: Today

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King AM-Series Main Bearings MB5278AM0.5

King AM-Series Main Bearings MB5278AM0.5

King AM-Series Main Bearings MB5278AM0.5

Main Bearings, AM-Series, Alecular Silicon, 0.50mm Crankshaft Undersize, Ford, 2.3, 2.5L, Set of 5

Part Number: KGB-MB5278AM05

Not Yet Reviewed

Estimated Ship Date: Apr 13, 2026 if ordered today

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Estimated Ship Date: Apr 13, 2026 if ordered today

King AM-Series Main Bearings MB5278AM0.75

King AM-Series Main Bearings MB5278AM0.75

King AM-Series Main Bearings MB5278AM0.75

Main Bearings, AM-Series, Alecular Silicon, 0.75mm Crankshaft Undersize, Ford, 2.3, 2.5L, Set of 5

Part Number: KGB-MB5278AM075

Not Yet Reviewed

Estimated Ship Date: Apr 13, 2026 if ordered today

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Estimated Ship Date: Apr 13, 2026 if ordered today

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