When I bought my John Deere 1070 a few years ago, the previous owner had just replaced ONE of the rear tires. It's a Kelly-Springfiled tire. When I was searching for KS tires I wasn't having any luck. Turns out KS has sold out. I think they sold out to Titan but I don't know how close of a match they would be. Will it hurt the tractor if the two rear tires aren't closely matched? The older tire still has good tread but it's getting "dry-rot" pretty bad so I'm looking for a new one.