Hatz Biplane Association

My plane was built using a IO-320 from a 1974 Decathlon. During my conditional inspection yesterday, I found that the seal between the exhaust and the tailpipe extension has burned through. Does anyone else have a similar set-up and know the name of the part I am looking for? I'm trying to find where I can purchase the part, but not sure what to even google at this point.

Looks like a standard automotive exhaust donut.

https://www.summitracing.com/search/par ... ut-gaskets

Thanks for the help. Think I found a usable option at the local auto (& aviation) store.