S&S CYCLE 129" Power Package Engine Performance Kit — 129", 4.320" bore, 11.0:1 compression, Black – 18-26 Softail, 25 Touring, 17-25 Trike

The 129" Power Package Engine Performance Kit converts a 107" M8 to a 129" big bore setup without case machining, retaining stock engine height and original engine serial numbers.

• Big bore 4.320" cylinder with 11.0:1 forged pistons
• S&S oil pump and cam plate with removable passage plugs for easy servicing
• Independent scavenge sections for the flywheel cavity and cam chest, each with debris screens and a magnet in the cam chest
• Increased oil flow capacity on feed and scavenge sides and an adjustable pressure relief valve that can be set with the unit installed
• Quickee pushrods with chrome pushrod tubes, S&S premium tappets and hard-anodized billet tappet cuffs
• S&S valve springs designed for cams up to 0.605" lift and HPT496 cam optimized for big bore applications
• MLS multi-layer steel head gasket and included 129 cam cover badge; works with stock crankcases and stock or S&S roller rocker arms
• Made in the USA