31-0172A 99-06 crankcase assembly, 3-3/4" STD bore. Black

This S&S crankcase assembly is a significant upgrade for 1999 to 2006 Touring models and 1999 to 2005 Dyna models, excluding Softail models. Sold as a set, these cases are CNC machined from high-strength heat-treated aluminum castings, offering far more durability than stock cases, particularly at the front motor mount. They feature a Timken-style sprocket shaft bearing to handle high-performance loads and are clearanced for cam lifts up to .675 inches and strokes up to 5 inches. The black finish provides a custom look, and the cases remain compatible with stock components like the oil pump and cam plate. Note that specific oil line installation kits are required for certain Dyna and Touring chassis applications to ensure proper fitment.