Get a new exhaust manifold to replace the old, damaged, or cracked factory component on your 2011-2016 Chevy/GMC 6.6L LML Duramax. For greater durability, most of the aftermarket exhaust manifolds offered are manufactured with high-silicon ductile iron. Due to heat cycles and age, exhaust manifolds can be prone to cracking and cause boost or exhaust leaks. This can rob you of power and reduce engine efficiency. You'll find top-notch brands such as AFE, BD-Power, ATS, Dorman, and more.