The XDP Billet Rocker Arm Valve Bridge Set XD382 are an excellent upgrade to the valvetrain in your modified 2008-2010 Ford 6.4L Powerstroke. The stock rocker arm bridges in your truck were engineered for stock output levels. The added load and stress from your modified Powerstroke can rapidly exceed the power that the rocker arm bridges can handle. These CNC machined rocker arm bridges from XDP are constructed from hardened 4140 chromoly for durability and are then Nitride coated to provide additional protection and friction reduction. Sold as a set.