I just switched my front brakes over to the 450 dual piston calipers. Much smoother and instant response. I upgraded my rear brakes many years ago when I upgraded to an 05' 450 swingarm, shock and linkage. I now have more than enough brake to stop with no fade. Spindles must be changed for this upgrade.I picked up some nice used calipers on ebay for 20 a piece and spindles for 15 each. Rotors are the same. Rear rotor is NOT the same nor is the rear brake stay.All in all I would consider this a really nice, cheap upgrade. We all build them to go faster but sometimes we forget we need to stop them as well!