A body 8 3/4 rear axle housing

I have an 8 3/4 rear housing that I need to order the steel brake line for, however I don't know what it came out of. I'm pretty sure I read somewhere that, depending on the year, the hole that the T-fitting and vent screw thread into is located in different spots. As best I could measure under the car, looked like the threaded hole is about 15 1/2 to 15 3/4 inches from the housing axle flange surface. Looked like the hole was just about where the axle tube started to transition to the curved part that holds the diff. Can anybody tell me what year or years this housing is so I can order the correct hard line for it? Thanks for any help.