I was talking to some guy a know last night, who owns quite a few 3rd gens. He said that his brother picked up a 4th gen exhaust from the junkyard and put it on his 89 iroc. Would this be possible on my 91 RS, and how much more performancce, better sound will it offer? Is it just as good as going aftermarket or no?

 

The muffler and tailpipes fit right in. As for the pipe that goes to the muffler and over the axle to the converter it has some different angles and requires a new pipe or changes to the 4th gen pipe. You can use your existing pipe and just hook up the 4th gen muffler and tail pipes. I have a Flowmaster from a 95Z on my IROC. Sound and power improvements wouldn't be anything great.