What is the horsepower limit for this rotating assembly?

With the standard ARP 8740 cap screws, this assembly is rated for up to 900 horsepower. If you upgrade to the optional ARP 2000 cap screws, the horsepower rating increases to 1,500 HP.

What materials are the components made from?

The crankshaft and connecting rods are constructed from 4340 forged steel. The pistons are made from 2618 forged aluminum, and the wrist pins are premium chrome moly.

Specifications

Brand: Manley Performance
Part #: 29555RX
UPC: 807298087450

Manley Rotating Assembly, BBC 555 4.250 STROKE/4.560/+43cc

Name: Manley Rotating Assembly, BBC 555 4.250 STROKE/4.560/+43cc
Brand: Manley Performance
SKU: manley-performance-manley-rotating-assembly-bbc-555-4-250-stroke-4-560-43cc-t14-880927
Price: 4087.67 USD
Availability: BackOrder

$4087.67

On Backorder

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

Manley Rotating Assembly, BBC 555 4.250 STROKE/4.560/+43cc. Handles up to 1500 HP.

Key Features

Fits Big Block Chevrolet (BBC) engines with a 555 cubic inch displacement.
Features a 4.250-inch stroke and a 4.560-inch bore with +43cc piston dish.
Includes a 4340 forged steel crankshaft for strength and durability.
Comes with 4340 forged steel H-beam connecting rods with 7/16-inch ARP 8740 cap screws.
Optional ARP 2000 cap screws are available for increased horsepower support.
Includes 2618 forged aluminum Platinum Series pistons with premium chrome moly wrist pins.

This rotating assembly is designed for Big Block Chevrolet (BBC) engines. Please verify compatibility with your specific engine build and specifications.

⚠️ 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

If you're building a serious big-block Chevrolet (BBC) engine, a strong rotating assembly is the heart of the operation. This Manley Performance rotating assembly is designed for the 555 cubic inch displacement, featuring a 4.250-inch stroke and a 4.560-inch bore with a +43cc piston dish. It's built to handle significant power, capable of supporting up to 900 horsepower with the standard ARP 8740 cap screws, and an impressive 1,500 horsepower when you opt for the ARP 2000 cap screws.

The foundation of this assembly is a 4340 forged steel crankshaft, chosen for its strength and reliability under high stress. Complementing the crankshaft are 4340 forged steel H-beam connecting rods. These rods are equipped with 7/16-inch ARP 8740 cap screws, known for their robust performance. For those pushing the limits, an upgrade to ARP 2000 cap screws is available, offering even greater clamping force and durability for extreme horsepower applications. The assembly also includes 2618 forged aluminum Platinum Series pistons, which are lightweight yet strong, paired with premium chrome moly wrist pins for smooth operation and longevity.

This rotating assembly is a well-built package for serious engine builds. Please note that this assembly is not CARB approved and cannot be shipped to California. It's important to consult with your engine builder to ensure this assembly meets the specific requirements and goals for your project.