Hi all, I've been working on getting the parts together for reassembly on my 4.3L Merc. I spotted a exhaust flapper laying in the exhaust bellows area so I took the Y pipe off to check it out. Both were laying in the pipe, one still had the pin but it was worn through also. So my question is , is it common for these to fall out? Is that an indication of a lot of run time on a 1994 boat. How long should they last? Are their improved aftermarket available? Or replace with OEM parts. I am working on putting in the 2001
4.3L industrial version GM V6. I decided to install with the cam that is in it and see how it does???