Air. A very important part to having a clean-running, efficient diesel. K&N has just released a new High-Flow intake system for the 2008 Ford Super Duty 6.4L Power Stroke Diesel. Tests show an increase of 16.4 hp at 2600 rpm over the stock Ford intake configuration. The new system draws air through a K&N High-Flow Air Filter that increases airflow and never needs to be replaced. Protecting the oversize cone-shaped air filter and isolating it from engine heat, is a powdercoated heat shield that replaces the truck's stock air box. Contact K&N Engineering at 800-858-3333 or visit www.knfilters.com.