What does the 0.25mm size mean for these bearings?

The 0.25mm designation means these bearings are 0.25 millimeters undersize. This is typically used when a crankshaft has been machined down to a smaller diameter to true it up or remove damage. Always ensure your crankshaft journal diameter matches the bearing specifications.

What is PMaxBlack and Radialock technology?

PMaxBlack is King's proprietary material that offers superior load capacity, making these bearings suitable for performance applications. Radialock is a design feature that helps achieve the correct crush height, ensuring the bearing stays securely in place within the engine block.

Do these bearings come with installation hardware?

This product is for the main race bearing set only. Installation hardware, such as main bearing bolts or crankshaft seals, are typically sold separately and should be sourced based on your vehicle's specific requirements.

Specifications

Brand: King Engine Bearings
Part #: MB5283XP0.25
UPC: 611500536038

King Engine Bearings Performance Main Race Bearing Set - Size 0.25mm

Name: King Engine Bearings Performance Main Race Bearing Set - Size 0.25mm
Brand: King Engine Bearings
SKU: king-engine-bearings-king-engine-bearings-performance-main-race-bearing-set-size-t14-4324556
Price: 139.40 USD
Availability: BackOrder

$139.40

On Backorder — Expected to ship by May 17, 2026

Order now to reserve yours — we'll ship as soon as stock arrives. Full refund if we're unable to fulfill.

King Engine Bearings Performance Main Race Bearing Set - Size 0.25mm. Features PMaxBlack for superior load capacity.

Key Features

Fits 1993-2010+ vehicles including Ford F-150, Ford Mustang, and Lincoln Continental.
Features PMaxBlack material for superior load capacity.
Incorporates Radialock technology for optimal crush height.
Constructed with a tri-metal copper-based material for durability.
This is a 0.25mm undersize bearing set.

⚠️ CA WARNING: This product can expose you to chemicals known to the State of California to cause cancer and/or birth defects or other reproductive harm. Learn more

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About this part

Product Details

If you're rebuilding the heart of your engine, getting the right main bearings is crucial for long-term performance and reliability. This set from King Engine Bearings is designed to handle the demands of a performance build, ensuring your crankshaft spins smoothly and stays properly supported. King has been specializing in bearings since 1960, focusing on making the best available.

These main bearings feature King's PMaxBlack material, which offers superior load capacity compared to standard bearings. They also incorporate Radialock technology, which helps achieve optimal crush height for a secure fit. The tri-metal copper-based construction provides a solid foundation for your engine's rotating assembly, helping to manage heat and friction effectively.

This set is 0.25mm undersize, which is important to note if you're machining your crankshaft. It fits a wide range of vehicles, including many Ford trucks and SUVs like the F-150 and Expedition, as well as the Ford Mustang. Always check the full fitment list to confirm compatibility with your specific application.