The heat shield between the exhaust manifold and the spark plug wires has rusted away on my truck. I am going to make new ones from either a sheet of aluminum or a sheet of galvanized steel I can pick up from tractor supply. The shielding is not in contact with the exhaust manifold so we are working with mostly radiant heat between the exhaust manifold and the heat shield. I like the idea of using the aluminum for its anti corrosion properties but i am concerned that the exhaust manifold might get too hot for the aluminum. Below are pictures of the heat shields i am going to make. As you can see the aftermarket shields are made from galvanized steel. Also the shielding is in very close proximity to the exhaust manifold and probably touching it in some places. This vehicle gets driven in the salt belt. What material would you use?