I have a digger of about the same size, it works great on my 1957, TO35.
Just be sure that the digger has the proper (soft) grade shear bolt installed and that you have a few extra shear bolts in the toolbox.
Note to file: shear bolts are much cheaper than replacing busted gears.
Also, when you bring home a 3pt hitch post hole digger, you will have many new friends, however they will want to borrow the digger.
My good friend borrowed mine to did 3 holes, within a week, his son wanted to borrow it to dig 60-70 holes for a fence on his father in laws farm. The old man could afford a new john deere tractor with loader, but not a post hole digger.
I said no, I was going to use it.
In addition it's dug holes for another friends pole barn.
Do you see a pattern here.
Good luck, they are great tools.