What is the bore size recommended for this rotating assembly?

This Manley rotating assembly is designed for a 4.560-inch bore size. This, combined with the 4.250-inch stroke and the +43cc piston dish, creates a 555 cubic inch displacement.

What is the difference between ARP 8740 and ARP 2000 cap screws?

The ARP 8740 cap screws are a strong standard for performance builds, supporting up to 900 horsepower. The optional ARP 2000 cap screws offer a higher tensile strength, allowing the assembly to support up to 1,500 horsepower.

Does this rotating assembly come with bearings?

This Manley rotating assembly includes the crankshaft, connecting rods, and pistons with wrist pins. Main and rod bearings are typically sold separately and should be chosen based on your specific engine build requirements and clearances.

Specifications

Brand: Manley Performance
Part #: 29555R
UPC: 807298080550

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-t14-880923
Price: 4069.89 USD
Availability: BackOrder

$4069.89

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. Built for serious power, supporting up to 1500 HP.

Key Features

Fits BBC engines.
Features a 4340 forged steel crankshaft with a 4.250-inch stroke.
Includes 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.
Comes with 2618 forged aluminum Platinum Series pistons.
Includes Premium Chrome Moly wrist pins.

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

⚠️ 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

Starting with a 4340 forged steel crankshaft, this Manley rotating assembly is built for serious performance. It's designed for BBC (Big Block Chevrolet) engines and features a 4.250-inch stroke, which is a common choice for building a 555 cubic inch displacement when paired with the 4.560-inch bore and +43cc piston dish volume. This combination offers a good balance of torque and high-RPM potential for a wide range of applications.

The connecting rods are also made from robust 4340 forged steel in an H-beam design, known for its strength and reliability under high stress. They come equipped with 7/16-inch ARP 8740 cap screws, a well-regarded fastener for performance builds. If you're aiming for the upper limits of its capability, you can opt for ARP 2000 cap screws, which are rated for even higher horsepower loads.

Complementing the crank and rods are 2618 forged aluminum pistons from Manley's Platinum Series. This material is chosen for its strength and ability to handle the heat and pressure of high-performance engines. These pistons include Premium Chrome Moly wrist pins, which are durable and designed to handle the reciprocating forces. With the standard ARP 8740 cap screws, this assembly is rated for up to 900 horsepower, and with the optional ARP 2000 cap screws, it can support an impressive 1,500 horsepower. Please note this assembly is not CARB approved and cannot be shipped to California.