S&S CYCLE 129" Power Package Engine Performance Kit - Gear Drive - Oil Cooled - Highlighted Fins - M8 310-1227

If you're running an M8 and want genuine power gains without major engine teardown, the S&S Cycle 129" Power Package delivers a straightforward path to 22 additional cubic inches of displacement. This bolt-together kit skips case machining entirely, pairing oversized cylinders with a purpose-matched cam and oil pump for reliable, responsive performance. You get the engineering of a professional build without the fabrication costs or downtime.

The independent scavenge sections manage oil flow efficiently across the flywheel cavity and cam chest, while a magnetic debris trap in the cam chest protects your oil pump from contamination. High-performance conical single-wire S&S valve springs maintain valve control at higher RPMs. Best of all, your original engine serial numbers remain intact, and removable passage plugs make routine maintenance straightforward.

• Displaces 129 cubic inches
• Oil-cooled design
• Highlighted fins finish
• M8 compatible
• No case machining required
• Big bore cylinders included
• Matching cam assembly
• Independent scavenge sections
• Cam chest magnetic trap
• S&S conical valve springs
• Retains serial numbers
• Removable passage plugs
• Made in USA
• MPN: 310-1227