S&S CYCLE 129" Power Package for M8 — 4.32" bore, 4-3/8" stroke, 11.0:1 compression – 18-23 Softail, 17-19, 21-23 Touring, 22 CVO, 17-23 Trike

🔧 The S&S 129" Power Package for M8 is a bolt-on big-bore kit engineered for high-performance street and race applications.

It converts a 107" M8 to 129" with no case machining required and includes forged pistons, premium tappets, and high-performance S&S 550 cams designed for big-bore use.

• 4.32" bore cylinders with 11.0:1 compression and forged pistons for strength and repeatable performance
• S&S oil pump and cam plate with blue anodized finish, adjustable pressure relief valve, and removable passage plugs for serviceability
• Independent scavenge sections for the flywheel cavity and cam chest, debris screens in pickups, and a magnet in the cam chest to protect the oil pump
• Quickee pushrods, S&S premium tappets, and hard-anodized billet tappet cuffs for durability
• Includes all necessary gaskets, bearings, and hardware for bolt-on installation; made in the USA

This kit increases oil flow capacity on both feed and scavenge sides and is built to provide reliable power and serviceability under demanding conditions.