Haven't measured mine yet and doubt if it would help but I do have a question, are you using stabilizers with turnbuckles? That would prevent the arms from getting against the tires. When my stabilizers are too loose that happens to mine when I have an implement attached. I doubt if the length of the arm would change that anyway. When I don't have an implement on the tractor, I use a small chain, strap or bungee cord to hold the lift arms towards each other and keep them from flapping into the tires.