Junkyard,

The silencer ring is simply a metal ring on the intake side of your turbo. It is held in by a snap ring on the 5.9's. From what I have heard there is no positive or negative effects from taking it out. It only makes the turbo louder. If you like the turbo whistle sound you can take it out with a small screwdriver. just work the snap ring out of the groove and it will slip out. I did it on my 5.9 and can't tell a differance in performance myself, but it sure does let that turbo sing. On the 6.7's it's totally differant and I wouldn't advise it on them. They are very differant. If you do decide to take it out just be carefull not to let the screw driver slip into the impeller!
Congrates on the new(used) truck! I'm sure you'll like it.