aFe 46-40011 BladeRunner Stainless Steel Exhaust ManifoldaFe 46 40011 BladeRunner Stainless Steel Exhaust Manifold Eliminate the costly exhaust manifold cracks prevalent in the factory exhaust manifold. The aFe Bladerunner exhaust manifold for the popular 5. 9L Dodge Ram Cummins sets the new standard. Constructed out of cast 304 stainless steel with a reinforcing rib for strength along the flange and ultra thick wall flange at the port. The BladeRunner exhaust manifold outflowed the factory exhaust by 23%