K & N, go with the name you've been told time and time again provides quality. I'm skeptical of the performance they say it provides though.
You never want to have TRUE duals on your truck, granted it will relieve back pressure in the engine, but your going to loose alot of torque. All you should do is leave your cats on, run the two pipes back about 4 feet, cross them together..take out the muffler, and than have it Y off to the two tips of pipes that you want at the back of your truck. Thats what I did with my 2005 Z71, and it sounds like a beast. Flowmaster is absolute garbage if your leaving your cats on. The performance is useless, and why pay that kinds of money if its not even gonna make your exhaust that much louder? I had Flowmaster's on mine, and I took them right back off and resold them. WAY to expensive for starters. and dont fall into this "Flowmaster is the best thing since sliced bread" mentality.
