so im i see lots of parts being swapped over from a yfz but i always wondered if anyone has tried to swap ltr450 part? well i have spare ltr and lt parts so i decided to try to combine parts to help out el diablo possibly update his 250 since he always helping me out. so this is what i found,
ltr disks bolt directly to the lt hub, the disk is cross drilled and is maybe .5 mm larger in diameter. i could barely feel the difference with my finger.
the caliper bracket holes from the ltr also line up with the lt hubs bc the ltr has mult holes, only problem is that the stock allen head bolt from the ltr has the washer on it and it contacts the caliper so i think if it was ground off it would clear. the only other issue i found was the stock shield also got in the way.
i test fitted the parts on hubs that were no mount on the quad so i dont know how they would fit or work on the actual quad itself. so of the benefits i believe that could come is having a twin piston caliper up front and lighter rotors. also, since the ltr isnt as old, parts should be easier to replace.

 Am I looking at this correctly? If so only @ half the pad is contacting the rotor.  In your first picture, If the caliper is bolted to the spindle then the brake disk needs to be bigger or mount should be redrilled to get proper brake pad contact.