My rear brake line that goes over the diff is rusting bad and I would like to change it before it breaks. A couple of questions came up from the auto stores when I called, is it single, double, or bubble flared? Also what size is it? Auto Zone has steel brake lines with the double -flared ends on for $6.99 for a 6 ft section( I believe thats what I need). Does anyone have info on what the specs are for the rear brake line?