Stock parts

thats a huge list, maybe take pics, that would go a long way to answering your question

well for one that im interested in what is the stock exhaust size ?

I think it is 2.25".

Really you can mod anythign and everything on the car cep the frame lol. Go look at unholy's tib (has a thread in members profile section) Perfect example of how whatever you can put your mind to and imagine, you can create and do. Limited by how deep you wallet is of course.

EDIT: Wait you mean you have aftermarket car and don't know what stock and whats not. Look threw here for pics of stock tibs and see if it's similar to you car, or better post a pic of the outside and the engine bay on here for us to see.Obviously if you have a catback or intake you'd know thats aftermarket. Also seeing as you name has 04tiburon I'm geussings it's an 04 lol If the stereo head until is kinda blocky, takes up whole thing, and says infinity then it's stock.

Stock piping is like 2".

It's pretty easy to tell what's stock and what's not. Just post some pics.