I posted last week about doing this, and now it is done...I highly recommend doing this. While I cannot confirm any real results as far as MPG or power increase, I can tell you all that the truck does feel a little more peppy...seat of the pants type difference. The sound on the other hand is really cool. It sounds just barely different than stock unitl 2500 rpm, where it all of a sudden sounds like a big block gasser...it is really cool at WOT! Also, at idle, the exhaust sounds like a giant hair dryer!...the whistle sound is apparent even at idle...all in all, it was really a very good mod for very little cash...BTW I left the kitty alone. I will try to post some sound clips when I have more time.