What does 'undersize 0.020IN' mean for these bearings?

This means the bearings are manufactured to be 0.020 inches smaller in diameter than standard size. This is necessary when the crankshaft journals have been machined down (ground) to remove wear or damage during an engine rebuild.

What kind of engines are these bearings best suited for?

These bearings are made with a bi-metal aluminum material and are ideal for engines that operate under low to medium load conditions. They are not typically recommended for high-performance or racing applications that experience extreme stress.

Does this set include all the main bearings needed for an engine rebuild?

Yes, this is a complete set of crankshaft main bearings designed to replace all the main bearings in the specified AMC and Jeep 390 and 401 engines.

Specifications

Brand: King Engine Bearings
Part #: MB5518AM020
UPC: 611500197420

King Engine Bearings AMC / Jeep 390 & 401 (Undersize 0.20IN) Crankshaft Main Bearing Set

Name: King Engine Bearings AMC / Jeep 390 & 401 (Undersize 0.20IN) Crankshaft Main Bearing Set
Brand: King Engine Bearings
SKU: king-engine-bearings-king-engine-bearings-amc-jeep-390-401-undersize-0-20in-cran-t14-432171
Price: 65.77 USD
Availability: BackOrder

$65.77

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King Engine Bearings AMC/Jeep 390 & 401 crankshaft main bearing set. Undersize 0.020IN. Ideal for low to medium-load engines.

Key Features

Fits a wide range of AMC and Jeep vehicles from 1966-1991.
Main bearing set is 0.020 inches undersize for machined crankshafts.
Constructed with a lead-free, environmentally safe composite material.
Features a bi-metal aluminum construction.
Ideal for low to medium-load engines.

⚠️ 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

Built with a lead-free, environmentally safe composite material, these King Engine Bearings crankshaft main bearings are a solid option for AMC and Jeep 390 and 401 V8 engines. They are specifically sized at 0.020 inches undersize, which is important when rebuilding or reconditioning an engine where the crankshaft journals may have been machined down to account for wear. This bi-metal aluminum construction is well-suited for engines that don't see extreme loads, offering reliable performance for everyday driving and moderate use.

King Engine Bearings has been specializing in engine bearings since 1960, focusing on providing well-built components. This set is designed to fit a wide range of AMC and Jeep vehicles from the late 1960s through the early 1990s, including popular models like the Jeep CJ series, Jeep Cherokee, and AMC Javelin. When rebuilding your engine, using bearings that match the specific needs of your application is key to longevity and smooth operation.