Originally Posted by rwenzing
Ford made a midyear change to the 4x4 rotors in 2003 from 11.28" to 12". They should bolt on but you'd also have to change to the steering knuckles from a late 2003+ 4x4. To the best of my knowledge, the calipers, pads and brackets did not change at all during the transition.
This is correct. To my knowledge, the only option is swapping to newer knuckles and newer rotors, then everything else is good to go. I don't recall any other upgrades other than the normal slotted rotors and upgraded pads.
The Cobra front brakes is a 2wd Ranger thing....though I plan to play with 98-02 knuckles and Cobra brakes to figure something out in the future and possibly may offer a conversion bracket for purchase.