I'm new to this site and have really enjoyed all the information. I hoping to pick up a 2002 Ram 1500 4x4 QC SLT Sport this weekend. The truck has 85,000 miles on it and is a real cream puff. It is all stock and has been very well cared for. I know the 5.9's aren't know for their gas mileage but I have been reading all the post about different mods for performance and increasing MPG. The TB mod and the CAI are two of the first mod I plan to look into. The TB air horn/porting mod is a no brainer. We have been drag racing for 20 years so I know that on any engine whether it be on our big 583 big block or my boys single cylinder Jr. Dragster engines, air flow makes HP. I have been looking at the stock air box and comparing to the pictures of the CAI systems I see. The stock air intake to the filter block look to go into the fender well. This looks similar to some of the aftermarket systems in that it isn't just pulling direct hot air from under the hood. The only issue I see with the using the stock filter box and a good K&N filter is the small inlet tube entering the box. I'm also guessing the duct going to the TB is larger as well. Oh by the way. I have use a TB spacer on a 1993 3.9 V6 Dakato I owned for several years. It worked well and offered noticable throttle response. I also put one on my 1993 GMC 1500 but didn't see much difference. I wordering is anyone has done all three mods. The TB air horn removal, CAI and a TB spacer plate.