I have a 2004 Mountaineer 4.6L v8, and currently have Flowmaster 40 series on my truck......it DEFINATELY sounds badass.....turns heads constantly.
If im driving thru an outlet of stores, people are always looking over expecting to see a mustang,camaro, anything but an SUV!

I cant imagine how good it would sound with some Long tubes, deleted cats, and custom exhaust, and a Cam set!
They have a cam upgrade for our SUV's and ive been tempted to try it out......i think it may include new rocker arms,etc......
But I already have my mustang sitting in the yard, so i really cant afford to put another vehicle down even temporarily.