I have an 03 chevy tahoe 4x4 with the 5.3. I bought it recently and one of the things i noticed was the nice crome tips sticking out each side by the rear wheels and the nice deep mellow rumble of the exhaust note. Well, I looked under the truck to find a Borla cat back system. which consisted of piping from the cat back to a Borla muffler which split the exhaust into two pipes on the back side of the muffler. I think this is called a 1 into 2 muffler set up. I don't know how much it cost. All I know is that it souds good inside and outside without being overly obtrusive.