mine is still using the std valves as well as my bias valve and its still too much coz the back wheels can lift off ground when breaking hard coz its stripped out.
i got rst master cylinder, split both lines into two, joined one pipe from each together and through a (under bonnet) bias valve then into the std valves then out to the back brakes, so ive effectively got one joined system instead of the std split diagnal fl + rr and fr + rl braking system