# S&S Cycle 2018+ M8 Softail Models MK-Series Crankcase Assembly

Building massive power reliably just got easier! Our new MK-Series B Crankcases can be paired with our 136" cylinder kit and 4 5/8" Stroker Crank to give you a rock-solid build. These cases scrape more oil than the stock ones, have a large volume sump, and fit in a stock frame without modification.

This Part Fits:

Year

Make

Model

Submodel

2018-2020

Harley-Davidson

FLDE Deluxe 107

Base

2018-2020

Harley-Davidson

FLFB Fat Boy 107

Base

2025-2026

Harley-Davidson

FLFB Fat Boy 117

Base

2018-2023

Harley-Davidson

FLFBS Fat Boy 114

Base

2018-2021

Harley-Davidson

FLHC Heritage Classic 107

Base

2026

Harley-Davidson

FLHC Heritage Classic 117

Base

2018-2024

Harley-Davidson

FLHCS Heritage Classic 114

Base

2018,2020-2024

Harley-Davidson

FLSB Sport Glide 107

Base

2018,2020-2021

Harley-Davidson

FLSL Softail Slim 107

Base

2025

Harley-Davidson

FLSTFI Fat Boy Gray Ghost

Base

2018-2020

Harley-Davidson

FXBB Street Bob 107

Base

2025-2026

Harley-Davidson

FXBB Street Bob 117

Base

2021-2024

Harley-Davidson

FXBBS Street Bob 114

Base

2018-2019

Harley-Davidson

FXBR Breakout 107

Base

2023-2026

Harley-Davidson

FXBR Breakout 117

Base

2018-2020

Harley-Davidson

FXBRS Breakout 114

Base

2019-2020

Harley-Davidson

FXDRS FXDR 114

Base

2018-2020

Harley-Davidson

FXFB Fat Bob 107

Base

2018-2023

Harley-Davidson

FXFBS Fat Bob 114

Base

2018-2020

Harley-Davidson

FXLR Low Rider 107

Base

2020-2021

Harley-Davidson

FXLRS Low Rider S 114

Base

2022-2026

Harley-Davidson

FXLRS Low Rider S 117

Base

2022-2026

Harley-Davidson

FXLRST Low Rider ST 117

Base

2022

Harley-Davidson

FXRST Low Rider El Diablo 117

Base

2020-2024

Harley-Davidson

FXST Softail Standard 107

Base

## Details

- **Price:** 4068.5 CAD
- **Vendor:** S&S Cycle
- **Type:** Crankshafts

## Variants

| Variant | Price | Available |
|---------|-------|-----------|
| Default Title | 4068.50 CAD | In stock |

## Images

- Photo - Primary

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> Source: [Standard Auto Part](https://www.standardautopart.com/products/s-s-cycle-2018-m8-softail-models-mk-series-crankcase-assembly)
> Updated: 2026-07-13