What does '.30mm undersize' mean for these bearings?

This means the bearings are manufactured to be slightly smaller than the original factory size. They are intended for use when the crankshaft journals have been machined down by 0.30mm (approximately 0.012 inches) to remove wear and create a smooth surface for the new bearings.

What vehicles commonly use this main bearing set?

This set is commonly used in 1955-1967 Chevrolet V8 vehicles. This includes popular models like the Bel Air, Biscayne, Impala, Camaro, Chevy II, and Corvette, provided they have the specified engine displacements.

Do I need to buy anything else to install these bearings?

Yes, for an engine rebuild, you will typically need engine assembly lubricant to coat the bearings before installation. It's also essential to ensure your crankshaft has been properly machined to the correct undersize for these bearings to function correctly.

ACL 1955-1967 Chevy V8 265/283/302/327 .30mm Oversized Main Bearing Set

Specifications

Brand: ACL
Part #: 5M429P-30
UPC: 9315726099650

ACL 1955-1967 Chevy V8 265/283/302/327 .30mm Oversized Main Bearing Set

Name: ACL 1955-1967 Chevy V8 265/283/302/327 .30mm Oversized Main Bearing Set
Brand: ACL
Price: 57.96 USD
Availability: InStock

$57.96

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ACL 1955-1967 Chevy V8 265/283/302/327 .30mm Oversized Main Bearing Set. Essential for engine rebuilds needing to correct worn crankshaft journals.

Key Features

Fits 1955-1967 Chevrolet V8 engines with 265, 283, 302, and 327 cubic inch displacements.
Main bearing set is .30mm undersize, intended for crankshafts machined to correct wear.
Well-built multi-layer bearing material with steel backing for durability.
Designed to help restore proper oil clearance and oil pressure in worn engines.
Includes bearings for the main journals of the crankshaft.

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Will this fit your vehicle?

Product Details

ACL has been making engine bearings for decades, and this main bearing set for your 1955-1967 Chevy V8 is one of their staples. When you're rebuilding an engine, especially one with a lot of miles, the main journals on the crankshaft can wear down. This set is designed to compensate for that wear, allowing you to get your engine back in spec without needing to replace the crankshaft itself. These are a .30mm undersize, which means they are meant for a crankshaft that has been machined down by 0.30mm (or about 0.012 inches) to create a fresh, smooth surface.

This set includes main bearings for engines like the 265, 283, 302, and 327 cubic inch V8s found in many classic Chevys. ACL uses a multi-layer bearing material with a steel backing for strength and a specific overlay for durability and proper oil film retention. This well-built construction helps ensure consistent oil pressure and smooth operation once your engine is back together. They fit right into the factory bearing saddles, making installation straightforward for a rebuild project.

When you're doing an engine rebuild, it's crucial to have all the right parts. Make sure you've checked your crankshaft journals for wear and had them machined to the correct undersize before ordering bearings. If you're unsure about the exact size needed, it's always best to consult your engine's service manual or a trusted machine shop.