Chucko,
I run a 4' rotary cutter on my 18hp Yanmar and my father runs one on his 16hp Mitsubishi. You may have to make adjustments by raising depth of cut or taking a smaller swath if the grass or weeds are exceptionally tall or thick. Other than that, the physical size and weight would be the only constraints. If you don't already have a FEL or other means of adding weight to the front, you will need that too.
Jeff