What does '0.010 inch undersize' mean for these main bearings?

This means the bearings are manufactured to be 0.010 inches smaller in diameter than standard. They are intended for use with a crankshaft that has been machined down by 0.010 inches, which is a common step in engine rebuilding to correct wear.

What vehicles does this main bearing set fit?

This set is compatible with a wide range of Pontiac V8 engines from 1963 to 1976, including those found in models such as the Bonneville, Catalina, Firebird, Grand Am, Grand Prix, and LeMans.

Are these bearings suitable for a performance engine build?

Yes, Clevite bearings are well-known for their robust construction and ability to handle increased stress. The multi-layer material and steel backing provide a strong foundation for both stock and modified Pontiac V8 engines.

Clevite Pontiac 421 428 455 V8 1963-76 Main Bearing Set

Specifications

Brand: Clevite
Part #: MS667P10
UPC: 027067540157

Clevite Pontiac 421 428 455 V8 1963-76 Main Bearing Set

Name: Clevite Pontiac 421 428 455 V8 1963-76 Main Bearing Set
Brand: Clevite
Price: 203.37 USD
Availability: InStock

$203.37

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Clevite main bearing set for Pontiac 421, 428, 455 V8 engines (1963-76). Features a 0.010 inch undersize for crankshaft regrinding.

Key Features

Fits 1963-1976 Pontiac 421, 428, and 455 V8 engines.
Main bearing set is 0.010 inch undersize for use with a reground crankshaft.
Multi-layer bearing material with a steel backing for durability.
Designed to handle the pressures and temperatures of V8 operation.
Helps maintain proper oil clearance and reduce crankshaft friction.
Fits a wide range of Pontiac vehicles including Bonneville, Catalina, and Grand Prix.

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Will this fit your vehicle?

Product Details

These Clevite main bearings are built to a 0.010 inch undersize, meaning they're designed to work with a crankshaft that has been reground by 0.010 inches. This is a common practice when rebuilding an engine to bring worn bearing surfaces back into spec. This set is specifically made for Pontiac V8 engines like the 421, 428, and 455, covering a wide range of years from 1963 to 1976.

When you're rebuilding the bottom end of your Pontiac V8, getting the main bearings right is crucial for engine longevity. Clevite uses a multi-layer bearing material with a steel backing for strength and a specific overlay designed to handle the pressures and temperatures found in these classic engines. This well-built set ensures a solid foundation for your crankshaft, helping to maintain proper oil clearance and reduce friction.

This set fits a variety of Pontiac models from the mid-60s through the mid-70s, including popular choices like the Bonneville, Catalina, and Grand Prix. If you're in the middle of a restoration or a performance build on one of these engines, these bearings are a solid option to consider for a reliable rebuild.