04-10 Duramax HSP Billet Valve Covers Color:Silk Satin Black It eliminates the possibility of

It eliminates the possibility of air being drawn into the system

The gear case alignment dowel pin nicknamed the "Killer Dowel Pin" or "KDP" has a tendency to vibrate loose or walk out of its bore

SW # 4 : 90 Hp increase

OEM up-pipes eventually fail from constant temperature and pressure fluctuation

04-10 Duramax HSP Billet Valve Covers Color:Silk Satin Black It eliminates the possibility ofOur billet valve covers are designed to give your engine a clean, sleek look. They feature a 1 2" NPT port in the center of the cover to optimize crank case ventilation. They are made from 6061 T6 Aluminum, and they incorporate an O Ring to eliminate the need for messy silicone. It is recommended to run these valve covers with our forward facing thermostat housing, for there are no provisions to mount the factory hardware to upper valve cover. Our