18" will be louder than stock, 24" is about stock noise level (a little louder) until you get on the gas. Are you gonna install it yourself, do you have any plans to replace the y-pipe?

 

sbdiehl

First off, I have the 5.7L, not the 5.9. I have an Aero Exhaust 3030XL on mine. I had the shop simply take the stock muffler off and replace it with the 3030XL and leave the stock resonaters in place. At idle it is barely louder than stock but when you put your foot into it there is a nice low rumble which is what I was looking for. I'm too old to be driving a truck around that sounds like a race car and I didn't want to wake the neighbors when I start the thing so that is how I ended up with what I have.

Here is a link to a post I made that has some video clips so that you can hear mine if you like. https://dodgeforum.com/forum/3rd-gen...-at3030xl.html

Again, remember I have the 5.7 Hemi, not the 5.9 so I don't know what, if any difference that would make. Also, the Aero Exhaust is a little more spendy than the Flowmasters or Magnaflows! Hope this helps.