SBM 340 4340 Forged Crank - 4.000 Stroke

The SBM 340 4340 Forged Crank with 4.000 Stroke from EAGLE is a precision-engineered crankshaft designed for small block Mopar engine builds and high-performance applications. Built for enthusiasts and professional engine builders who demand reliability in street, strip, and race environments, this forged steel component replaces worn or stock cranks while providing superior strength and durability. The internal balance design ensures smooth operation and reduces vibration across a wide RPM range, making it an ideal choice for both naturally aspirated and forced-induction builds.

Manufactured from 4340 forged steel, this crankshaft delivers exceptional tensile strength and fatigue resistance compared to cast alternatives, enabling higher horsepower and torque outputs without compromising longevity. The 4.000-inch stroke increases displacement and low-end torque production, making it a popular choice for stroker engine packages that prioritize mid-range power delivery. The two-piece seal configuration allows for straightforward installation and maintenance, while internal balancing eliminates the need for external balance weights, simplifying the overall engine assembly process and improving aesthetics in bay-visible builds.

Small block Mopar builders—from drag racers to street performers—rely on the SBM 340 4340 Forged Crank to achieve consistent, repeatable power increases through displacement expansion. Installation requires proper alignment with compatible connecting rods, pistons, and engine block specifications to ensure correct clearances and zero-deck geometry. Weighing 64 lbs and measuring 32.5 inches in length, this crankshaft is engineered to OEM tolerances and proven in thousands of builds across the Mopar performance community. Verify compatibility with your specific small block Mopar platform and connecting rod length before purchase to guarantee proper fit and function.