Yeah I realize the differences with cheap stainless and good pure stainless. I've used 409 too and know it's not as good but I haven't even seen 409 stainless rust this quickly. And it is rust, not discoloration. After all the trouble I had installing this kit that was supposed to be a bolt on (with the normal mods to make it fit headers) it's just another straw on the Camel's back. I wouldn't recommend it to anyone.