What is the exhaust manifold made of: Steel or cast iron? My guess is steel, but others have disageed. I ask this because in trying to free the nuts from the manifold to turbo housing, I ended up punching a hole in the exhaust manifold. Now I need to welder.
stock GN headers and Xover pipes are made of 409 stainless steel, it is a magnetic material and gets brittle when heat is applied. must be cleaned properly before welding
