Need help with which muffler this is

[UP Brett]

I bought this muffler used but can not find part # any where on it. See attached pic. I tried 3" for a hd bagger and it sounds like I would like, but JWells said I had 2 much power and to try a 4", so thats what I'm doing, don't want to be breaking parts.
The muffler has a 16" body and 2" inlet and a 2-1/2" outlet. I need to add some intrenal disc's and bolts to go with them. Was told it was for a 93 zx6.
I'm putting it on a 2008 Yamaha FX Nytro 4-stroke snowmobile.

Thank you for any and all help,
Brett