I have the 4.8l in my truck and when I put my superchip in, I felt like I was driving a completely different vehicle. As far as my exhaust sounds,
http://www.gmtruckclub.com/forum/showthread.php?t=32339 that is the link to the pictures and the exhaust video of my truck. I posted the pictures first then replied with the video below. Let me know what you think!