I recently purchased a 1983 Z-28, I just noticed that instead of 1 big muffler there is 2 small mufflers with 2 pipes connecting the two together. They fit in the normal area that the 1 normal muffler fits. I haven't looked at the rest of the exhaust yet to see if there is anything else different.

 

Yep, it's stock. I think the I pipe should split into two and go into each muffler. I always wondered how that set up performs compared to the single muffler set up.

 

We will find out soon enough. I have that set up, but needed some parts. Could not find the same thing up here so I just went with Borla system. They told me the stock style you are talking about was a tuned system. I had no complaints about the sound or performance of my system now. But it is on an 84 and it is original and starting to fail at one of the dual pipes going over the rear end. I have even had to change the exhaust clamps over the years ,they have rusted right off , but exhaust is original. But I look forward to the change

 

I really didn't look under the car yet, I just noticed the 2 mufflers by the way it is parked. I have a major exhaust leak and haven't had time to locate it yet. The reason that I thought that it was not stock is that I found a book that shops use at a second hand book store that shows the exhaust parts and this set up was not listed on any of the Camaros or Firebirds it only showed the standard single muffler with either 1 or 2 tailpipes.