Mufflers for the 5.7L

I think cats sill still make some difference, though probably less than they used to. My parents had an 05 Ram I pulled the muffler and resonator off of once and it was definitely quieter than I expected, though when you got on it it was still pretty dang loud.

It's always hard to tell how exhaust will react on different cars, pipe sizes and lengths make a big difference. One of the guys at my work was talking to Flowmaster or someone a while back and they were telling him how the length of pipe after the muffler (to the tailpipe) makes a big difference in killing drone and changing tone. You can tune your sound by just changing that and not touching the muffler.