8 and 3/4 rear in a riding mower

Back in the 70s my father and uncle had a high school project where they built a garden tractor.

They used a 64 mustang v6
mopar a833 with a second a833 trans to get a low and high gear.
Then narrowed an 8 3/4 rear (unknown gear ratio)
Open exhaust. (That sound Got me into hot rods)
The tractor is about 5 foot wheelbase.
I will have to remember to take a pic tonight.
He never finished the body panels but when she is running it sounds mean. As a young boy it was the cats *** when she fired up -:)