I have a rear caliper from an '03-'05 yz450 that I was going to mount on my '02 426. The entire unit from the 450 is smaller and I guess slightly lighter but the brake pads are also slightly smaller (the width measuring front to back as if it was on the bike). Everything mounts up fine and the height (top to bottom) of the pads are the same so they contact the rear disk the same. Does anyone have any thoughts on the smaller pad (I would say 4/5ths the size of the 426 pad). Smaller and lighter is always nice but I don't think I want to sacrifice any braking power.