A couple of 23x10-12 Carlisle AT489 Titans and 55lb wheel weights. overkill? i hope so.
Good tires and more weight on them does make a difference with the light rear end on the Craftsman GT5000 and GT6000s.
As to your overkill, not at all overkill. My GT6000 has 26x10.50-12 Titan Mud Monster tires with 100 pounds of weight on each rear wheel. Few days ago I threw another 40 pounds on the left side to help with plowing traction this weekend. I can't get to any of my previous pic uploads from my iPad, so I will have to go find one of them and copy it over here in next post.