We have a Challenger 45 with mirrors and I agree, they work. We also have a jd 8400t and an 8100 tire. The tire machine has the JD external mirrors and they also work well. The 8300T does not have the external mirrors and there is no way the JD mirrors would ever stay on if they were there. There might be a way to put mirrors on a T (maybe if the brackets were made out of 4" x 3/8 tubing :-)) that would stay but the JD ones sure would not - they would be shaken to pieces the first trip down a washboard road. I like running the Deere better in the field, better about everything than the Challenger, but there is no question the Cat roads better.

John