This is probably an odd question, but I actually like the size of the stock exhaust tips. Are there any aftermarket exhaust with that same size, or all they all 3.5"-4"? I think the bigger exhaust tips just make the rear end look too fat, but I don't want the stock sound.

 

You can always have 2.5" tips welded on

 

Would that change the sound of the exhaust if I did that?

 

Depends, if its akin to something like an SLP Loudmouth the double wall tip forms a chamber which changes the sound.

To get a significant change you would have to play around with the mufflers and/or their placement.