What material are these main bearings made from?

These main bearings are made from a bimetal material that has an aluminum silicon base. This construction is chosen for its balance of wear resistance and thermal properties.

What does the '+0.75mm' size indicate?

The '+0.75mm' indicates that these bearings are slightly larger than standard size, by 0.75 millimeters. This sizing is typically used when the crankshaft journals have been machined undersize during an engine rebuild.

Are these bearings a direct replacement for all Chevrolet 121 engines?

These bearings are specifically sized at +0.75mm, which is not a standard size. They are intended for engines where the crankshaft has been machined to accommodate this undersize bearing during a rebuild.

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Specifications

Brand: King Engine Bearings
Part #: MB5531SI0.75
UPC: 611500466014

King Engine Bearings Chevrolet 121 (Size +0.75mm) Main Bearing Set

Name: King Engine Bearings Chevrolet 121 (Size +0.75mm) Main Bearing Set
Brand: King Engine Bearings
SKU: king-engine-bearings-king-engine-bearings-chevrolet-121-size-0-75mm-main-bearing-t14-770794
Price: 68.79 USD
Availability: BackOrder

$68.79

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King Engine Bearings Chevrolet 121 (Size +0.75mm) Main Bearing Set. Engine Bearing.

Key Features

This set includes main bearings for a Chevrolet 121 engine.
Bearings are sized +0.75mm for specific engine builds.
Constructed from a bimetal material with an aluminum silicon base.

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About this part

Product Details

In this set, you get the main bearings needed for your Chevrolet 121 engine, specifically sized at +0.75mm. These bearings are constructed from a bimetal material with an aluminum silicon base, which is a common and effective choice for engine components.

These bearings are designed to provide a reliable interface between your crankshaft and the engine block. The aluminum silicon base offers good wear resistance and thermal conductivity, helping to manage heat and reduce friction in a critical part of your engine's rotating assembly. Having the correct size bearings is crucial for proper oil clearance and engine health.