How do I find an 8 3/4 rear in the jy

8 1/4 started in 73 in 340 cars and some 318 cars. This was also the changeover year to big bolt pattern.
I recently parted a 71 swinger slant six car that had an 8 3/4 in it. I had no idea until I got the car home and jacked it up. So never say never, anything can have one in it.