What does '.020 undersize' mean for these bearings?

This means the bearings are manufactured to be 0.020 inches smaller in diameter than standard. They are intended for use when the engine's crankshaft has been machined down by 0.020 inches to correct wear or runout.

What is trimetal construction?

Trimetal bearings have three layers of different materials. This construction is common in performance and racing applications because it offers excellent load-carrying capacity and durability compared to simpler bearing designs.

What is the pMax Black coating?

The pMax Black coating is an advanced surface treatment applied by King Engine Bearings. It's designed to reduce friction between the bearing and the crankshaft, and it also helps to improve oil flow and retention for better lubrication.

Specifications

Brand: King Engine Bearings
Part #: MB5381XP020
UPC: 611500537035

King Engine Bearings Holden 253/308CI 5.0L/5.7L (Size .020) Main Bearing Set

Name: King Engine Bearings Holden 253/308CI 5.0L/5.7L (Size .020) Main Bearing Set
Brand: King Engine Bearings
SKU: king-engine-bearings-king-engine-bearings-holden-253-308ci-5-0l-5-7l-size-020-ma-t14-532209
Price: 112.88 USD
Availability: BackOrder

$112.88

On Backorder

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

This is a King Engine Bearings main bearing set for Holden 253/308CI 5.0L/5.7L engines, sized .020 undersize.

Key Features

This is a King Engine Bearings main bearing set.
Designed for Holden 253 and 308 cubic inch (5.0L/5.7L) engines.
The set is .020 inch undersize, for use with a machined crankshaft.
Features trimetal construction for durability and load capacity.
Includes pMax Black coating for improved friction reduction and oil retention.

Secure CheckoutFast Shipping631-982-0042

About this part

Product Details

You're getting a set of main bearings from King Engine Bearings, specifically the MB5381XP020 model. These are designed for Holden 253 and 308 cubic inch engines, which are typically 5.0L or 5.7L displacements. This particular set is .020 inch undersize, meaning it's intended for crankshafts that have been machined down by that amount during an engine rebuild.

These are race bearings, built with a trimetal construction. This means they have multiple layers of different materials, which helps them handle the high loads and temperatures found in performance or rebuilt engines. The pMax Black coating is an advanced surface treatment that King uses to reduce friction and improve oil retention, helping to keep your bearings cool and well-lubricated under demanding conditions.