I have done some reading about guys that raced the 450rs back in 2004/05 swapping to the ltz450r knuckles but that's a totally different machine from what I understand, you are probably right. Glad the 400ex calipers bolted right up along with the rotors. Now to get a caliper rebuild kit for the calipers I have and a master cylinder. I hate frankinestine projects that I didn't build lol it's been a mystery the entire time I've been rebuilding this 250r one weird part after another lol
thanks for your help!