I see that this is a little old, but in case anyone reads this in the future, I just want to make sure they make an informed descision. I've always heard that header wraps are BAD NEWS!!! They keep TOO much heat in, and the header can't handle it, and will crack. And from what I hear, the Jeep 4.0 header is already a little prone to cracking. I know, the first time I heard that I was like "whatever", but I've read plenty of articles since then that have changed my mind. In fact, most header manufacturers will VOID the warranty if there is any evidence that header wrap was used. Here's one article I managed to go back and dig up http://www.centuryperformance.com/ex...e-spg-138.html
I'm not saying there may not be benefits to it too, but to me the drawbacks are far worse. You make your own descision on your Jeep, but hopefully make an informed one.