If you don't have rear wheel weights, consider that before a ballast box, as it is dead weight, doesn't effect manuvering in tight places, and doesn't add a strain to the tractor as much as a rear ballast box. You can probably use the same 1/2 plate on the wheel weights if you happen to have it used...then use 1/8 on a ballast box and you will actually be able to move the ballast box out of your way when it is sitting somewhere, without having to hook it up to the tractor.
David from jax