The Jeep headers aren't a bolt in setup, they have to be done custom from the collector back. It will make better power and torque with two pipes when the go fast stuff goes on. 3" would be cheaper and easier, but the headers are set up to run duals. I will probably do 2.5" on each side and a nice X under the passenger side.
http://www.dodgetalk.com/forums/show...ighlight=kooks