Most antique tractors when pulling needs about 14-15 pounds in their tires, however it could be more or less depending on the rules of the competition you are entering. There is also a drawbar rule, it is to be a minimum of two square inches in total steel at any point, as well must be rigid in all directions. The hitching device can be no more than 1 1/2 inch round stock (1 1/2 square), or less than 1 1/8 inch round stock (1 inch square), the hole has to be 3"X3 3/4"- inch diameter. The drawbar on a tractor should be no shorter than 18 inches from the center of the rear axle to the point of the hitch. All the weights that are on your tractor has to be non-moveable, they have to be safety secured to the tractor, bungee cords are not allowed to be used. All drivers when pulling need to remain seated, if they get out of there seat they could face disqualification. However, all these rules can change depending on what competition you go to.