There are two different models of the 501, a short pitman version designed for smaller utilities, like the Ford N-series, and a long pitman version, designed for larger tractors like the Ford 5000 and my JD 2010RC. The short pitman version normally was equipped with triangular shaped stabilizer brackets which pivoted on an extension of the 3pt hitch arm lift pins with the opposite point being clamped to the 3pt hitch lower lift arm. The long pitman version depended on the stabilizers built into the tractor (like the "elephant ears" on the larger John Deeres) and had a single clamp mechanism onto the left 3pt hitch arm to lift the outer end of the cutterbar when raising the mower. This clamping mechanism was designed for the larger 3pt lift arms.
That said, while the mower can most likely be made to fit your tractor, find a pitmanless mower of you want to mow other than horizontal.