517988 Sprocket shaft, special application

This special application sprocket shaft from MCS is designed for custom engine configurations, specifically when fitting 1972 to early 1981 Big Twin wheels into 1965–1969 Big Twin cases. Unlike standard shafts, this version is manufactured without a keyway, catering to specific performance or custom build requirements. When you are mixing and matching components from different eras of the Big Twin engine, having the right conversion shaft is critical for proper alignment and fitment within the primary drive. This shaft provides a solution for builders working on unique Shovelhead or early Evo-style bottom ends where standard off-the-shelf parts won't suffice.