Manley 290300RH SBC 434 CID Rotating Assembly 4.000" Stroke +4cc Dome Pistons

The Manley 290300RH is a complete, precision-balanced rotating assembly engineered for Chevy Small Block (SBC) stroker builds displacing 434 cubic inches. Built around a 4.000" stroke and 4.155" bore with 350 main journals, this assembly delivers high-compression performance with +4cc dome forged pistons — making it an ideal foundation for serious street/strip and race engine builds.

At the heart of this kit is a Manley 4340 forged steel crankshaft that is heat-treated, nitrided, stress-relieved, shot-peened, and magnafluxed for maximum strength and reliability. Micro-polished journals, gun-drilled mains, and lightened rod journals contribute to both durability and reduced rotating mass. The assembly is precision internally balanced in-house by Manley.

The connecting rods are Manley 6.000" H-beam units forged from 4340 alloy, fully machined, heat-treated, stress-relieved, shot-peened, and magnafluxed. They are bronze-bushed for full-floating pin applications and secured with ARP rod bolts for reliable clamping force at high RPM.

Pistons are Manley Platinum Series 2618 forged aluminum with a +4cc dome profile and lateral gas ports, paired with premium Chrome Moly wrist pins. Compression ratio varies by head chamber volume: approximately 14.7:1 with 58cc chambers, 13.6:1 with 64cc chambers, and 11.8:1 with 76cc chambers. The assembly is completed with ductile moly file-fit rings (.043" x .043" x 3/16") and Clevite H-series rod and main bearings.

Key Specifications:

• Displacement: 434 CID
• Stroke: 4.000"
• Bore: 4.155"
• Main Journal: 350 (2-piece rear main seal)
• Rod Length: 6.000"
• Piston: Manley Platinum Series 2618 Forged, +4cc Dome, Lateral Gas Ports
• Compression Height: 1.100"
• Compression Ratio: 14.7:1 @ 58cc / 13.6:1 @ 64cc / 11.8:1 @ 76cc
• Crankshaft: Manley 4340 Forged Steel, Non-Twist Lightweight Design
• Connecting Rods: Manley 4340 H-Beam, Bronze Bushed, ARP Rod Bolts
• Rings: Ductile Moly File-Fit .043" x .043" x 3/16"
• Bearings: Clevite H-Series Rod and Main
• Balance: Precision Internally Balanced (Neutral)

The Manley 290300RH rotating assembly is a complete, ready-to-install solution for builders targeting high-compression naturally aspirated SBC stroker applications. Its all-forged, name-brand component lineup ensures long-term reliability in demanding performance environments.