S&S Cycle 99-06 BT 4in Bore 4in Stroke Cylinder Kit - Wrinkle Black w/ HighlightInspired by our Pro Stock Drag Race engines, these updated big bore kit utilizes a Ductile Cast Iron liner wrapped in cast aluminum for optimum thermal conductivity and performance. Bolt in kits do not require machining, rebalancing or engine removal, and include just about everything you'll need to complete the installation. The biggest cylinder bore that can be installed in a stock crankcase without machining! This Part Fits: Year Make Model