My question is what grade of stainless would people use for a saltwater injected marine exhaust system. This will be a replacement for the original that was built many years ago out of mild steel. I have been getting mixed answers 304 versus 316. 316 sounds to have a greater resistance to saltwater unless the SW is warm. This system has a SW injection pump to cool the exhaust before leaving the exhaust manifold. Any input?

Thank you,