I have a Gibson swept side on my 4.6L. Performance is great but not happy with the sound. It is just a little to quiet for me. Was thinking of going to a Magnaflow. Just the muffler and keeping my pipes since they are only 3 months old. Anyone have any opinions?

 

Look at a cutaway of the flowmasters. Tons of noise making baffles that are bound to make backpressure, ie rob power. I switched to a magnaflow and it has a straight through pipe that you can look clear through. It is way more quiet than my old flowmaster but I want power and not noise.