Brake Line: 82-83 Camaro Firebird REAR Drum across Diff.. AF threadFor 1982 and 1983 Camaro and Firebird models with rear drum brakes, this brake line features the original AF thread. While most 1984 models switched to metric threads, some early '84 vehicles or those with differential changes may still require this AF threaded line. This part ensures proper fitment for those specific applications. THIS IS FOR mainly 82 & 83's with AF threads two brake lines. pre bent ready to install.