These exhaust manifolds are the product of 8 months of R&D in our engineering department! Made from two chunks of Billet steel, they go through a few different processes before they are complete! These manifolds are direct bolt on (for the engine side) for any 03-07 6.0 & 08-10 6.4 Powerstroke. They will require custom up-pipes to work, but they are awesome for custom high performance set ups! They come standard with 2" V-Band outlets. In time, these will be offered as complete drop in kits with high flow up pipes as well! These Manifolds are not only pure art, but they work extremely well! Dyno Numbers are soon to come!