What is the horsepower rating for this rotating assembly?

This Manley rotating assembly is rated for up to 900 horsepower when using the standard 7/16? ARP 8740 connecting rod cap screws. With the optional ARP 2000 cap screws, the assembly can support up to 1,500 horsepower.

What materials are the crankshaft, connecting rods, and pistons made from?

The crankshaft and connecting rods are constructed from strong 4340 forged steel. The pistons are made from 2618 forged aluminum, and they include Premium Chrome Moly wrist pins.

Are there any restrictions on shipping or use for this product?

Yes, this rotating assembly is not CARB approved and cannot be shipped to California. It is intended for off-road or racing applications where emissions compliance is not a factor.

Specifications

Brand: Manley Performance
Part #: 39555RHX
UPC: 807298086859

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-t14-880993
Price: 4273.61 USD
Availability: BackOrder

$4273.61

On Backorder

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Manley Performance BBC 555 rotating assembly. 4.250" stroke, 4340 forged steel crank and rods.

Key Features

Fits BBC (Big Block Chevrolet) engines.
4.250 inch stroke configuration.
4.560 inch bore with +43cc piston dish volume.
Includes a 4340 forged steel crankshaft for strength.
Comes with 4340 forged steel H-beam connecting rods.
Connecting rods feature 7/16? ARP 8740 cap screws, with an option for ARP 2000.

This rotating assembly is designed for BBC (Big Block Chevrolet) engines. Please verify compatibility with your specific engine block and cylinder head combination.

⚠️ 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

This Manley Performance rotating assembly is built for BBC (Big Block Chevrolet) engines, specifically configured for a 555 cubic inch displacement with a 4.250 inch stroke and a 4.560 inch bore. It's a well-built package designed to handle significant power, making it a solid choice for serious engine builds where performance is key. The components are selected to work together seamlessly, providing a strong foundation for your engine.

At the heart of this assembly is a 4340 forged steel crankshaft, chosen for its strength and durability under high stress. Paired with it are 4340 forged steel H-beam connecting rods. These rods come standard with 7/16? ARP 8740 cap screws, a popular choice for their reliability. For those pushing the limits, there's an option to upgrade to ARP 2000 cap screws, which can support even higher horsepower levels. The pistons are Manley's Platinum Series, made from 2618 forged aluminum and include Premium Chrome Moly wrist pins, ensuring they can withstand the demands of a high-performance engine. This combination is rated for up to 900 horsepower with the standard ARP 8740 bolts, and an impressive 1,500 horsepower when using the optional ARP 2000 cap screws.

When assembling your engine, pay close attention to the manufacturer's instructions for proper installation and torque specifications, especially concerning the connecting rod caps and piston installation. This assembly is not CARB approved and cannot be shipped to California. Please verify fitment for your specific application before ordering.