What is the horsepower limit for this rotating assembly?

With the standard ARP 8740 cap screws on the connecting rods, this assembly is rated for up to 900 horsepower. Upgrading to ARP 2000 cap screws increases the capacity to 1,500 horsepower.

What materials are the main components made from?

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

Specifications

Brand: Manley Performance
Part #: 29555H
UPC: 807298080543

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-t14-880920
Price: 4072.77 USD
Availability: BackOrder

$4072.77

On Backorder

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Manley Performance BBC 555 rotating assembly, 4.250" stroke. Handles up to 1500 HP.

Key Features

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

This rotating assembly is designed for Big Block Chevrolet (BBC) 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

Manley Performance is well-known for making strong internal engine components, and this BBC rotating assembly is a prime example of their commitment to robust builds. This 555 cubic inch assembly is designed for big block Chevrolet engines, featuring a 4.250 inch stroke and pistons with a 4.560 inch bore and a +43cc dish. It’s built to handle serious power, capable of supporting up to 900 horsepower with the standard ARP 8740 cap screws on the connecting rods, and an impressive 1,500 horsepower when you opt for the ARP 2000 cap screws.

The heart of this assembly is a 4340 forged steel crankshaft, chosen for its strength and durability under high stress. Paired with this are 4340 forged steel H-beam connecting rods, which are known for their excellent strength-to-weight ratio. These rods come ready for 7/16? ARP 8740 cap screws, with an option to upgrade to ARP 2000 cap screws for even greater reliability at higher power levels. The pistons are Manley's own Platinum Series, made from 2618 forged aluminum for good thermal stability and strength, and they include Premium Chrome Moly wrist pins.

This rotating assembly is a solid foundation for a high-performance engine build. Please note that this part is not CARB approved and cannot be shipped to California. Always refer to the manufacturer's installation instructions for proper assembly and torque specifications.