I used to be a MagnaFlow dealer. Go with Magnaflow, they are the best performance wise. When they design a kit for a vehicle, it must make horsepower improvements or they won't put it out to market. They try several designs until they find one that makes the most power. Then they build jig for it so they come out perfect every time. Only I'm not a dealer is I'm too small of volume for them (I only sell 1 or 2 a year). I am still a MAC Performance dealer, but they don't do cat backs for Dodge or Chevy right now. They cut back to focus on Fords since that's what they started out with. Any way, I'm going with Magnaflow on my Hemi Ram. I think they're the best out there.