not done this on a z32 but I seem to recall there is a problem where the pipe passes between the underside and the rear subframe. Apparently it's possible to do it with the subframe in situ but very tricky. The easiest way is to drop the rear subframe but this is a pig. Some peeps have re-routed the pipe. Maybe someone will know better?
The pipe has split just infront of the rear wheel just as it goes to up over the sub frame, and I then believe then it goes to the actual brake capliper. I have about 10 ft of solid brake line, which i have been told is new stuff and better than stock as it wont go rusty.
I think I will re route the line from the drivers rear to passenger rear.