Skip to content

Cart

Your cart is empty

Find parts for your rideFind your bikeHide bike finder
Browse all parts

Choose from the vehicle applications currently listed in our catalog. Engine sizes refer to the standard engine.

Bike not listed or engine modified? Contact us to check fitment.

S&S, M8 107" to 124" big bore piston kit. STD

Supplier SKU: 580354
Sale price£663.42

Availability: Out of stock
Estimated supplier restock: 2 November 2026 Supplier estimate, subject to change. Delivery time is additional once stock arrives.

The details that matter

Details

Description

11.1:1 compression ratio. Piston kit includes forged pistons, rings, wristpins and clips. Crankcases do not require boring. Big bore 4.250" cylinders are required, OEM cylinders can not be bored to 4.250". 107" to 124" pistons come with 1.143" deck height and are compatible with the OEM 107" 4.375" stroke.



Note: For 4.250" big bore cylinders only see S&S 574121 (black wrinkle) or 547122 (black wrinkle with higlighted fins).

Note: Gaskets are sold separately as 591055 head gaskets, 591054 base gaskets or 591056 head & base gasket kit.

Note: S&S recommends an S&S 550 series cam, which are available in both chain or gear drive.

Note: In any and all applications the technician must be able to judge components for their suitability in combination with the other engine components, prior to installation. It is of importance that a knowledgeable mechanic will install & make adjustments as required. The rider must follow standard break-in and riding procedures for overhauled engines.

Specifications

Unit KIT

Fitment

18-24 107" Softail; 17-24 107" FLT/Touring (NU)

Part numbers

Supplier SKU 580354
Manufacturer part 920-0135

Specifications

BrandS&S
CategoryPistons and rings kits

Fitment

Part numbers

Need a hand choosing? Talk to the workshop