I replaced all four calipers on my disco I along with rotors. Up front I used the bigger 110 calipers and vented rotors. I also used s/s flex lines, Ferodo pads and new hardware too. The front calipers did require fabricating new hard lines at the swivel balls. A quart of new brake fluid was used through the bleed portion. I can report that this truck actually stops now. Really stops! I can lock up the tires on dry pavement if I want to. It has never remotely performed like this before. The confidence of having functioning brakes cannot be overstated.