is there such a thing as a 8 1/4?

the 8 1/4" rear has 3" axletubes and the 7 1/4" rears have 2½" axletubes also a good way of id these axles, the 8 1/4" rear has 10 bolts to hold the cover and i think the 7 1/4" rear has 9 but i am not sure about it...