310-1351 M8 Softail MK-Series crankcase assembly. Large bore

This black S&S MK-Series crankcase assembly is the ultimate starting point for a high-performance 2018 to 2026 Milwaukee-Eight Softail build. Designed to handle the stresses of massive power, these cases feature a 4-1/2 inch large bore with a 4.695 inch spigot bore. S&S has improved upon the stock design by including a machined oil scraper to prevent oil dragging on the flywheels and a larger volume sump for better lubrication. These cases maintain the stock deck height and are designed to bolt directly into the factory frame. If you are looking to build a large-displacement M8 Softail that lasts, these heavy-duty cases provide the strength and precision required.