Need a socket or wrench for a 8-3/4 plug

70DusterBob,
Im a bit confused.
Does your plug have a recessed square? If so you need to insert this:
Screenshot_20201220-080643_Gallery.jpg
You're referring to what you need as a SOCKET.
Or is it like these pics?
20201220_080044.jpg
20201220_075947.jpg
If its like these pics, I've always had success using an adjustable crescent wrench, like mentioned above.
Worst case scenario, use a smaller plumbers pipe wrench, but that will gouge the square head.
You can always replace with a replacement standard pipe plug.
Screenshot_20201220-080754_Chrome.jpg
Joe