Here are some mode I had to do to adap my attachement . On the box blade had to cut relocate the 1/2 plate for the pin
I built the same. Always on my tractor.
I have something similar but mounted on a 300 lb elevator weight that also acts as my counterweight on my CUT.
The elevator weight is real handy as it is 'tucked in' close thus adding little or no overhang and that coupled with tires juice filled works just great.