Manley 290330RX SBC 434 CID Rotating Assembly Kit 4.000" Stroke / 4.155" Bore

The Manley 290330RX is a complete Small Block Chevy (SBC) 434 CID rotating assembly kit featuring a 4.000-inch stroke paired with a 4.155-inch bore. Engineered by Manley Performance — one of the most respected names in high-performance engine components — this kit delivers a precision-built, internally balanced rotating assembly ready for serious street/strip and competition builds.

Kit Components Include:

• Manley 4340 forged steel crankshaft — 4.000" stroke, 350 main journal, non-twist lightweight design; heat treated, stress relieved, shot peened, nitrided, and 100% Magnaflux inspected
• Manley 4340 forged steel H-beam connecting rods — 6.000" length with ARP 2000 cap screws (rated to 1,500 hp); heat treated, stress relieved, shot peened, nitrided, and 100% Magnaflux inspected
• Manley forged aluminum pistons — 4.155" bore diameter with a 1.100" compression height
• Manley premium chromoly wrist pins
• Total Seal piston rings — 1/16" – 1/16" – 3/16" ring package

Assembly Notes:

• Precision internally balanced by Manley in-house
• Designed for 2-piece rear main seal blocks with 350 main journals
• Requires aftermarket or appropriately prepped block for 4.000" stroke clearance

The Manley 290330RX rotating assembly is the ideal foundation for a high-displacement SBC stroker build, combining race-proven metallurgy and in-house balancing to ensure reliable, consistent performance.