Hey guys. I’m new here so forgive me if this has been answered already. Got a 2001 400ex that I bought from a guy. He said he thinks the axle is from a 2005 450r which he said the caliper needs to be a 450r caliper. Anyone know how I can verify that this is indeed a 450r rotor? Perhaps what is the diameter of a 400ex vs a 450r? Just want to make sure and avoid ordering the wrong caliper.