Replace the old, cracked, or damaged exhaust manifold on your 2007.5-2010 Chevy/GMC 6.6L LMM Duramax and get your engine running right. A failed exhaust manifold often cracks, or leaks, from heat cycles, age, and other conditions. This can result in boost leaks, or exhaust leaks that can reduce engine efficiency and rob you of power. Durable, high-silicon ductile iron manifolds are offered as an upgrade or stock replacement for many applications. BD-Power, Dorman, AFE, ATS, and many more are just some of the manufacturers you can find.