S&S Cycle 99-05 BT Super Stock 89cc Cylinder Head Kit - Silver

This is the S&S Cycle Super Stock 89cc Cylinder Head Kit, designed to fit 1999 through 2005 Big Twin Harley-Davidson engines. If you're looking to improve the breathing and power output of your stock displacement engine, or even a larger stroker or big bore setup up to 110 cubic inches, these heads are a solid choice. They offer a slightly higher compression ratio than stock with their 89cc combustion chambers, making them particularly well-suited for touring bikes and other heavy vehicles where consistent low and midrange power is important.

What sets these heads apart is their ability to move more air. The large 2.000-inch intake valves and 1.605-inch exhaust valves are key here. They help maintain good port velocity for responsive low-end and midrange performance, while also supplying enough airflow for larger displacement engines to reach their full potential. In fact, these intake ports flow 264 cfm, a significant improvement over the stock 182 cfm. The included S&S High Performance valve springs are strong enough to handle camshafts with up to .650-inch lift, giving you flexibility for further engine modifications. Plus, they are designed to work with your stock rocker boxes, exhaust, and intake manifolds, simplifying installation. The silver powder coat finish also helps them blend in with your existing silver engine components.

This kit is a comprehensive upgrade for your Big Twin's engine. It includes everything you need to get these performance heads installed, and they are compatible with your existing rocker boxes, exhaust, and intake manifolds. This makes for a more straightforward installation process, allowing you to get back on the road sooner.