You have several options when it comes to adding weight. One way is to add fluid to the tires. Depending on how cold your area gets you can use water to a liquid that doesn't freezes. I would recomend you use innner tubes if you go that route.
Another way is to add wheel weight. Some buy factory weights. I use this set up on 2 of my Cubs.
Here are few pictures of the weight bracket:
The weights are 10 pound barbell weights that were purchase from wal mart.
I usually run 20-30 pounds heavier on the land side( left side) than the furrow side.
Here a topic that may help:
http://www.onlycubcadets.net/forum/s...=wheel+weights