GM LS 4340 Forged Crank 4.000 Stroke/6.125 Rod

The GM LS 4340 Forged Crank 4.000 Stroke/6.125 Rod is designed for serious LS engine builders and high-performance shops seeking maximum durability in stroker applications. This crankshaft is engineered for enthusiasts who demand reliability in forced-induction, nitrous, and competition builds where factory internals simply won't survive repeated cycles at elevated power levels.

Forged from premium 4340 chrome-molybdenum steel, this crankshaft delivers superior fatigue resistance and impact strength compared to cast alternatives, which is critical when supporting high combustion pressures and inertial loads. The 4.000-inch stroke combined with the 6.125-inch rod length creates the geometric foundation for stroker displacement increases while maintaining optimal piston speeds and rod angles for efficient long-block geometry.

This crank is ideal for LS1, LS2, and LS3 block builders planning displacement increases beyond stock 6.0L or 6.2L configurations. EAGLE's precision forging process and tight tolerances ensure proper journal sizing, reducing friction losses and extending bearing life even under sustained high-load conditions typical of turbo, supercharged, or large-displacement naturally aspirated platforms.