Building a custom baffle need some insight/input.

[JaR3d85]

Alright so here it goes, just got my carpenter sidewinder and I know it's going to be loud. I don't care about my neighbors simply because they don't care about being dicks. Anyways, so I have a 2.25 perforated core 20 inch long I didn't realize that the 02 sensor location would prohibit my original idea of running the core all the way too the end on of the megaphone, so I'm trying to figure out how to do this without too much trial and error. Everything chat gpt has told me is that I don't want any contact on the inside of the megaphone accept for the stainless mesh I'm using to keep the packing and stainless wool in place. I guess my question is for anyone who has a better understanding of the assembly of something like this, I don't want it to rattle and I will be welding the core to the end cap I'm going to turn, does the core essentially end up just feel floating? The end that goes into the pipe? I attached a generated image of what chat gpt says will work. Any input is greatly appreciated. I was leaning more towards the more real looking image. The info on the drawings isn't completely correct so anything that mentions aluminum is false and will be stainless and the O2 sensor placement is very wrong along with actual dimensions other than the 4.375 diameter.. to 2.25 diameter.