Are you talking about the removable stinger in the tail pipe? Some one told me that you should be good just leaving it in on the 2.5 and the 3.3.
I have the trinity Pipe. It came with two headers, springs, gaskets and the pipe. On the package it said it would fit a 2.5 and 3.3. I'm running it on my OS .21tm right now. I had to use the stock OS header because the Trinity header won't work on the .21tm. I read that the bigger header is for big blocks. Haven't broke in my 3.3 since I got it back from Traxxas.