310-1351 S&S M8 Softail MK-Series crankcase assembly. Large bore for Harley-Davidson
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Specifications
- Brand
- S&S
- Part Number
- 310-1351
- OEM Reference
- —
- Pack Quantity
- Each
- Category
- Crankcases
- VAT Rate
- 20%
About This Product
S&S MK-Series large bore crankcase assembly in black for 2018 to 2026 Milwaukee-Eight Softail models. Bore size is 4-1/2 inch with a 4.695 inch spigot bore. The cases have a machined oil scraper to prevent oil dragging on the flywheels. The sump volume is larger for better lubrication. Stock deck height is maintained. They bolt straight into the factory frame. These cases handle the stress of a big-power M8 Softail build.
Manufacturer part number: 310-1351.
Fitment
24 models18-26 M8 Softail
Softail 24 models
| Brand | Year | Model |
|---|---|---|
| Harley-Davidson | 2025–2026 | Breakout FXBR |
| Harley-Davidson | 2018 | Breakout 114 Anniversary FXBRS |
| Harley-Davidson | 2018–2022 | Breakout 114 FXBRS |
| Harley-Davidson | 2023–2024 | Breakout FXBR |
| Harley-Davidson | 2018–2020 | Deluxe FLDE |
| Harley-Davidson | 2018–2024 | Fat Bob 114 FXFBS |
| Harley-Davidson | 2018–2020 | Fat Bob FXFB |
| Harley-Davidson | 2025–2026 | Fat Boy FLFB |
| Harley-Davidson | 2018 | Fat Boy 114 Anniversary FLFBS |
| Harley-Davidson | 2018–2024 | Fat Boy 114 FLFBS |
| Harley-Davidson | 2018–2020 | Fat Boy FLFB |
| Harley-Davidson | 2025–2026 | Heritage Classic FLHC |
| Harley-Davidson | 2018 | Heritage Classic 114 Anniversary FLHCS |
| Harley-Davidson | 2018–2024 | Heritage Classic 114 FLHCS |
| Harley-Davidson | 2018–2021 | Heritage Classic FLHC |
| Harley-Davidson | 2025–2026 | Low Rider S FXLRS |
| Harley-Davidson | 2020–2022 | Low Rider S FXLRS |
| Harley-Davidson | 2025–2026 | Low Rider ST FXLRST |
| Harley-Davidson | 2018–2021 | Slim FLSL |
| Harley-Davidson | 2019–2020 | Softail Slim FLSL |
| Harley-Davidson | 2018–2024 | Sport Glide FLSB |
| Harley-Davidson | 2025–2026 | Street Bob FXBB |
| Harley-Davidson | 2021–2024 | Street Bob 114 FXBBS |
| Harley-Davidson | 2018–2020 | Street Bob FXBB |
Planning other changes? Find your model in the bike customiser.
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