On my 7.3 I had dual 7" curve top stacks. They were loud and definitely got attention anywhere I went. If you’re looking for that head turning action, a stack will do it. Sometimes it gets good and bad attention though. I can agree that for a DD, stacks do get old. They are right there all the time, right behind your head BAWWWWWW all they time. While you’re on the phone, on the highway- the drone, people in the back seat getting annoyed, so on. There cool to show off, don't get me wrong, but you have to deal with them in the mean time.
For my 6.4 set up I stayed with a 5" single straight pipe. At idle, it's way in the back, but when you get on it, it's there and loud. If anything, I had thought about going to a dual rear set up. I am definitely happy with what I have now, a much cleaner look, less offensive for a DD, and easier to hear yourself think while driving lol.
Here is a shot of the 7" stacks... LOUD is an understatement.
