OK guys, the muffler that came on the Z/28 I'm doing is a flow master 3" inlet dual 2.5" outlet. No idea of the mileage but this is the type that just uses all metal Construction so they last a long time. I'm in Arizona where rust isn't an issue. For a used muffler it's in great shape. No markings on it other than flow master. Thinking shipping will be $20-30. I don't know which it is so I don't know what a fair price is. Just make an honest and reasonable offer and I'll accept. FYI if you offer me $10 plus $20 shipping I'm not even going to reply.