Rick I am very interested to hear what you have done. I just picked up an 04 Supercab Lariat 4X4 with the 6.0, auto trans. I only have 1200 miles on it so far, but love the truck. I am a little scared after reading all the post about poor fuel ecomomy and loss of power. I am switching from two Dodges with the Cummins. Great engines, 18-20 on the eway at 70+ consistently, unloaded. Once saw 19 pulling a 26' inclosed car hauler with two Jeeps in it. Reason for Buying the Ford is a long story. In short I ordered a Dodge in April and in July Chrysler canceled the order becasue they were going into '05 production. They told me 6-8 weeks for the order, and never indicated the order would be canceled at any point. Feel the blood pressure rising better stop that story here.
I have a preluber to have full oil pressure when I hit starter. I also have an Oil Guard bypass filter to clean oil to 1-2 microns which makes oil last longer under most conditions. I have AFE Air Guard 7 intake air filter. I put in 55 gal replacement fuel tank. I put in Banks 4" monster exhaust from turbo back. I bypassed cat converter & unplugged erg valve. I just installed Jucie by Edgeproducts which is what they call a flip-chip along with the in-cab monitor. bought 11 of 2003 & has "08 Sept 03" on FICM. The truck was in shop at 2000 miles because it would not maintain an rpm out of gear without "hunting". I guess it was flashed. Have NEVER had 1 concern with truck whatsoever. Runs fantastic, lots of power even though I have only gotten on it a handfull of times. My only concern with truck is to drive it easy, take the best care of it because my vehicles usually last forever. I'm not a speed demon at all & drive with a very light foot. This is true especially with 11,500 lb 5th wheel or 5,500 lb utility trailer for heating/ac jobs.