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

This means the bearings are manufactured to be 0.010 inches smaller in diameter than a standard-sized bearing. This is typically used when the crankshaft journals have been machined down (ground undersize) to remove wear or damage. Always confirm your crankshaft journal size with your machinist before ordering.

Are these bearings suitable for a stock engine rebuild?

Yes, while they are part of ACL's Race Series, they are a well-built option for any Ford V8 engine rebuild, including stock applications. They offer improved durability over standard bearings.

Do I need any special tools to install main bearings?

You'll need basic engine rebuilding tools, including a torque wrench to tighten the main caps to spec. It's also highly recommended to use Plastigage to verify oil clearance after installation, ensuring the crankshaft spins freely without excessive play.

ACL Engine Crankshaft Main Bearing Set 5M590H-10

Name: ACL Ford Prod. V8 255-289-302 Race Series Engine Crankshaft Main Bearing Set
Brand: ACL
SKU: acl-acl-ford-prod-v8-255-289-302-race-series-engine-crankshaft-main-bearing-set-t14-630835
Price: 109.94 USD
Availability: BackOrder

ACL Ford Prod. V8 255-289-302 Race Series Engine Crankshaft Main Bearing Set

$109.94

On Backorder

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

ACL Ford V8 Race Series crankshaft main bearing set for 255-289-302 engines. Built for performance applications.

Key Features

Fits many Ford V8 engines including 255, 289, and 302.
ACL Race Series crankshaft main bearing set.
Bearing size is 0.010 inches undersize.
Features a specialized overlay material for durability.
Designed for performance engine builds.

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Will this fit your vehicle?

Product Details

Doing a rebuild on your Ford V8 engine, likely a 255, 289, or 302? These ACL Race Series crankshaft main bearings are a solid choice for getting your engine back in shape, especially if you're aiming for a bit more performance or just want a well-built replacement. Main bearings are critical for keeping your crankshaft spinning smoothly within the engine block, and a good set ensures proper oil clearance and reduced friction.

ACL has been around for a while, and their Race Series bearings are known for being well-built with a focus on durability. They use a specialized overlay material that's designed to handle the demands of higher performance engines. This particular set, part number 5M590H-10, is sized at 0.010 inches undersize, which is important to note if you've already had your crankshaft machined. Make sure your machinist has accounted for this size when preparing the crank journals.

When you're putting these in, remember to check your oil clearances carefully with Plastigage to ensure they're within the manufacturer's specifications. Proper installation and attention to detail here will make a big difference in the longevity and performance of your engine build.