Well, you could lift it and put a duramax in it.
If you want to hear it whine, then definitely take the muffler off. In Oregon, you don't have to take your truck through DEQ, so you could take the cat off as well and that helps with the exhaust flow. You could order a bigger exhaust from Rubberduck, or I know a guy in Gresham that can make you a new one for the same money.
My husbands Excursion has a straight pipe and it's LOUD! (6.0L)