Our 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 additional breather kit will include all the necessary hardware to route the breathers behind the front cab mounts. This reroute will feature a 1/2" NPT to -10AN aluminum 90° fitting to a -10AN nylon braided hose on each valve cover. This is an additional product that is not included with the standard valve covers. You must select the crank case ventilation kit in the drop-down menu if you wish to purchase it.