Manley 290140HX SBC Rotating Assembly Stroke Bore Flat Top - 383 3.750 4.040 4cc

The Manley 290140HX is a high-performance rotating assembly kit engineered for Small Block Chevy (SBC) 383 cubic inch stroker builds. Featuring a 3.750-inch stroke crankshaft paired with a 4.040-inch bore, this kit provides everything needed to build a powerful and reliable 383ci bottom end from the ground up.

At the heart of this assembly is a lightweight 4340 forged steel crankshaft, paired with 4340 forged steel H-beam connecting rods secured with 7/16-inch ARP 8740 cap screws — rated to 750 hp in standard configuration, with an optional upgrade to ARP 2000 cap screws supporting up to 1,500 hp. The pistons are Manley's 2618 alloy Platinum Series forged aluminum flat top (-4cc) pistons, machined with Manley's unique single-operation fixturing to ensure precise ring groove-to-skirt squareness for optimal ring seal.

Kit Includes:

• Lightweight 4340 forged steel crankshaft — 3.750-inch stroke, 2-piece rear main seal
• 4040-inch bore 2618 Platinum Series forged aluminum pistons (-4cc flat top)
• 4340 forged steel H-beam connecting rods with 7/16-inch ARP 8740 cap screws
• Premium chromoly wrist pins
• Total Seal piston rings
• Clevite "H" Series narrowed rod bearings
• Clevite "P" or "H" Series main engine bearings

Key Specifications:

• Engine Family: Small Block Chevy (SBC)
• Displacement: 383 cubic inches (6.3L)
• Stroke: 3.750 inches
• Bore: 4.040 inches
• Piston Style: -4cc Flat Top
• Rear Main Seal: 2-piece
• Balance: Unbalanced (external balancing required)
• Horsepower Rating: 750 hp (ARP 8740) / up to 1,500 hp (optional ARP 2000)

The Manley 290140HX rotating assembly is the ideal foundation for a serious high-performance SBC 383 stroker engine build, whether for street, strip, or competition use. Professional engine builders and elite tuners trust Manley components for their precision manufacturing and proven durability under extreme power levels.