Upgrade or replace the old, damaged, or cracked exhaust manifold on your 2003-2007 Ford 6.0L Powerstroke to restore proper operation to your engine. For greater durability, most of the aftermarket exhaust manifolds offered are manufactured with high-silicon ductile iron. Exhaust manifolds can fail due to cracks or leaks from heat cycles, age, and other extreme conditions. These leaks can reduce power, and also hurt engine efficiency. You'll find top-notch brands such as AFE, BD-Power, ATS, Dorman, and more.