Here's our Z, with headers and a Pypes 2 1/2" mandrel system with their transverse muffler.
With 2 1/2" tail pipes
https://youtu.be/5dTNw93VPEQ
And again with the stock 2" tail pipes grafted in.
https://youtu.be/IZ0HlEY7b74
Here's our Formula with the exact same system but with stock exhaust manifolds up front.
https://youtu.be/uIFkggwDY-8
I'll have to dig up some other clips if interested of the GTO and my BB chevelle. The Chevelle is 2" super comps with 3" exhaust, Dr. Gas X with Dynomax Ultraflows and Torque Tech tailpipes. The GTO is similar but with 3 1/2" into a Dr Gas that reduces to 3" and some little race mufflers on it, forget the brand name.