I have a 2003 F-250 with a 5.4, trying to get the pro's and cons of exhaust. I pull a 5th wheel with this and want the best of both worlds economy and torque. I want a nice sound but too old to wear ear plugs on a daily driver. I have added K&N cold air and a Poweraide TBS. Now to the exhaust it has the baby coffin muffler and I want to get rid of this and go Flow master or equivalent. My concern is that I let it breath on top but the restriction in the Y pipe bothers me. Should I make changes there and go dual exhaust or look at putting on a good free flowing cat with a one in two out muffler. I been looking at this a lot and am worried about back pressure. I am not trying to make this a race truck but it would not hurt my feelings to have it turn a few heads. I am old but not dead. Any help from you veterans of the 5.4 would be appreciated. Thanks, Don

 

I also am looking at adding a Bully Dog tuner into this mix

 

Performance gains will vary dependent upon your set up,The more power the vehicle makes, the bigger the gains will be. Flowmaster sounds great, MBRP, is also a good option.