I wrte another thread on mods to get or not get....but there was an article on exhaust systems and the amazing engineering that goes into our stock systems...really.

As mentioned in a prior response, a dual exhaust system may actually kill some speed off the line and may drop your mpg.

If you look at NASCAR those engines are wide open at 6,000 rpm or to 9 grand ? , we drive (if we're legal) in the 1,800 to 2,300 rpm range. The CAI, headers, CAT back, etc may sound cool and if thats what you want thats fine.

lessons learned,
I put a GIBSON CAT back on my Dakota V6, sounded great but would give you a headache over 10 miles / 10 minutes..as the sound resonated within the cab and would resonate in your head. I did have a flowmaster muffler before that which was inbetween the GIBSON NASCAR blaster and the stock but have not done anything to my RAM so not sure what to tell you.

I just bought a K&N Stock replacement air filter but on my Camry and a prior Honda the CAI systems normally increases the under hood noise especailly when you get on it...guessing the HEMI would sound really good and then at normal cruise probably be quiet enough. It looks cool but really does not make that much differance compared to stock unless you are running wide open, but a few horsepower may get 1 more mile to the gallon and if you plan to keep your truck for ten years or so, it may pay to make the mods early.

I'm looking to get some titanuim JBA headers, wrap them with exhaust copper impreganated insulation tape (cloth) and and keep the stock exhaust system (at least until it rusts out...) will let you know what the K&N filter does and when I get the headers installed.