Well got the new 4" exhaust on this weekend. pinnacleperformance. took about 5 hours. with the help of two perfectionest.:ro) dont like the way it goes under the cab. had a little clearance but not enough. when starting and passenger it rubs a little on bottom of cab. but not down the hi-way. sounds great, not too much difference in cab for noise. hear turbo again and little more performance. but will have to go back and modify where it goes under cab. I took pics and will get them on here as soon as I figure out how to do it.. I guess when you buy aftermarket, sometimes you have to modify....... off to work..