What's needed for going to a Disc brake rear-end?

Allright, if I were able to get a disc brake rear end out of another third-gen, what else would need to be changed? Could I run the smae brake lines or no?

Unless you found a 89 or later rear(early disc set-ups were crap) with the PBR 11.655 rotors and aluminum calipers I would not waste the time or money. But if its the 89 or later, all you would need to change is the Proportioning valve.

Allright, thank you very much. :)