I picked up a 5" SS from RPM about 6 months ago,it has a 4"down pipe that tapers to 5" before the muffler.It is a little louder than I would like, didnt seem to change myfuel milage but dropped my egt's by about 100 deg. The exhaust was actually built by flo pro http://www.flopro.com/mufflersounds.htm.


2003 CTD 2500
A few mods