What does the 0.25mm undersize mean for my engine build?

The 0.25mm undersize specification means these bearings are designed to fit crankshaft main journals that have been machined down by 0.25mm. This is a common practice during engine rebuilding if the original journals have wear or damage.

What is the material of these main bearings?

These main bearings are made from a bi-metal aluminum material. This type of construction is chosen for its suitability in medium-load engine applications.

Are these bearings environmentally friendly?

Yes, these bearings feature a lead-free composite and are considered environmentally safe. King Engine Bearings focuses on producing high-quality, responsible engine components.

Specifications

Brand: King Engine Bearings
Part #: MB5257SI0.25
UPC: 611500435584

King Engine Bearings General Motors 379/V8 Ohv (Size +0.25mm) Main Bearing Set

Name: King Engine Bearings General Motors 379/V8 Ohv (Size +0.25mm) Main Bearing Set
Brand: King Engine Bearings
SKU: king-engine-bearings-king-engine-bearings-general-motors-379-v8-ohv-size-0-25mm--t14-770599
Price: 71.35 USD
Availability: BackOrder

$71.35

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King Engine Bearings main bearing set MB5257SI0.25. Fits many GM 379/V8 OHV engines. 0.25mm undersize.

Key Features

Fits a wide range of General Motors 379/V8 OHV engines.
Main bearing set is 0.25mm undersize for use with machined crankshaft journals.
Constructed with a bi-metal aluminum material suitable for medium-load engines.
Features a lead-free composite that is environmentally safe.
King Engine Bearings has specialized in bearing production since 1960.

⚠️ 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 bottom end of a General Motors 379 cubic inch V8 OHV engine, this main bearing set from King Engine Bearings is a solid option. These bearings are specifically sized at 0.25mm undersize, which is important if your crankshaft journals have been machined down during the rebuild process. King has been specializing in engine bearings since 1960, focusing on producing high-quality components for a wide range of applications.

This particular set uses a bi-metal aluminum material, which is well-suited for medium-load engines. They are also lead-free and environmentally safe, making them a responsible choice for your build. King's commitment to specialization means they've developed a deep understanding of bearing technology, aiming to provide reliable performance for your engine's critical rotating assembly.

This set fits a broad range of vehicles, including many Chevrolet C/K series trucks and SUVs from the 80s and 90s, as well as AM General Hummer models from the 90s. Always ensure your crankshaft journals have been measured and machined to the correct undersize before installing these bearings.