S&S CYCLE Engine Performance Kit — 129", 4.320" bore, 11.0:1, 4.375" stroke – 18-26 Softail, 24-26 Touring, 17-26 Trike, 25 CVO

Upgrade compatible with M8 models, including VVT models, with a big bore bolt-on design that increases a 107" M8 to 129" without case machining.

Built around an S&S oil pump/cam plate with removable passage plugs for service, independent scavenge sections for the flywheel cavity and cam chest, and debris screens in both scavenge pickups.

A magnet in the cam chest helps reduce debris reaching the oil pump, while increased oil flow capacity on both feed and scavenge sides supports performance use.

Includes an adjustable pressure relief valve, Quickee pushrods with pushrod tubes, S&S premium tappets, black-coated tappet cuffs, S&S valve springs, a 496 camshaft, and an MLS head gasket.

Compatible with the stock and S&S roller rocker arms, retains stock engine height, works with stock crankcases, and keeps original engine serial numbers intact. Made in the USA.