2.5" exhaust vs 2.25 or even 2"

I hope you don't mean you want to put old school exhaust on there.:realcrazy:
What’s an old school exhaust?
True duals? LMAO!
Before you bring mufflers into it.....
You can get that old school sound by choosing the right mufflers.
Very true. The rhythm to the sound is the cam.
I always suggest a good high flowing muffler but many want a certain sound and I get that but it is also subjective and it is a personal choice on what you think sounds right.

To that end, I then suggest to attend a car meet and when you hear what you want, track down that car owner and ask questions. Not just what mufflers he is running.

Engine size, compression, cam specs and “How the exhaust is constructed.”