You probably did see car wheels on a Cub. But it was probably a 5 hole pattern, lots of old Chrysler and Ford cars used that same 5 hole bolt pattern as the Cub, (but the lug holes may have been a bit larger.) I am also thinking someone had a list of other make wheels that would fit the Cub bolt pattern. I saw it a few years back, I don't know where.
To use your wheels, you are probably going to have to find an adapter or else drill and tap the axle flanges for the 4 hole pattern, if you don't mind doing that to your axles.