Welcome to thee place to get info on your CTD.
You will soon find that there are many that know and some that just do things cause the other guy did it. I feel for the "get rid of the clogged converter", I wrestled that thing off to find , at 150K miles, there was no sign of clogging... oh well. There are clogging stories at 25K miles... hummm.
On the silencer ring, it is there to minimize the turbo inlet noise. Located on the compressor side and held in place by a spring ring when removed (mines not), your truck will whine more, some like noise some do not. As for performance some will say it spools up faster and goes faster... ... ... they probably went faster with playing cards in their bicycle spokes!
This is my opinion and you are intitled to it! I anticipate flames on this one... . so what!
Again welcome aboard and enjoy your truck!
Mike