Has anyone installed one? If so do you see any added pep? Any better fuel economy? Please give details of your ride if you've done this. When the factory get's done mine will be a Laramie MegaCab 2500 4WD 5.7L. I put one on my '08 MegaCab 4wd 1500 and noticed a little bit on the interstate (maybe 1-1.5mpg better) but I wondered how the newer Hemi's react to the thing.