Manley 28555 Big Block Chevy CID Rotating Assembly Stroke Bore Flat Top - 555 4.250 4.560 3cc

The Manley 28555 is a complete Big Block Chevy rotating assembly engineered for serious street and race applications. Built around a 4.250" stroke and a 4.560" bore, this kit displaces 555 cubic inches and delivers a low-compression -3cc flat-top piston configuration suited to forced induction or high-compression naturally aspirated builds targeting compression ratios from approximately 9.0:1 to 9.4:1 depending on head chamber volume. This kit requires a 9.800" tall deck block.

Key Features:

• Crankshaft: Manley 4340 non-twist lightweight forged steel, 4.250" stroke — heat treated, stress relieved, shot peened, nitrided, and 100% magnafluxed; precision internally balanced in-house
• Connecting Rods: 4340 forged steel H-Beam design, 6.385" length, fitted with 7/16" ARP 8740 cap screws (ARP 2000 upgrade optional); rated to 900 HP with ARP 8740 or 1,500 HP with ARP 2000
• Pistons: Manley Platinum Series 2618 forged aluminum, 4.560" bore, -3cc flat-top design; includes premium Chrome Moly wrist pins
• Piston Rings: High-performance Classic Race ring set — ductile iron plasma moly-inlaid top ring, reverse-twist cast iron taper-face second ring, three-piece oil ring
• Bearings: Clevite "H" Series rod bearings (narrowed) and "P" or "H" Series main bearings included
• Balance: Precision internally balanced by Manley to within +/- 1% of bobweight
• Block Requirement: Designed for 9.800" tall deck Big Block Chevy blocks

Compression ratios of 9.0:1, 9.4:1, or 9.8:1 are achievable depending on combustion chamber size. Upgrade to ARP 2000 cap screws (sold separately) to push the horsepower ceiling to 1,500 HP. This rotating assembly provides a solid foundation for high-output BBC builds combining proven Manley forging quality across every rotating component.