Should have been type 3. Type 5 did not exist then. I would STRONGLY urge you to consider converting it to tandom master cylinder. This requires the tandem master, some brake tube workover, and a distribution block "maybe." If you don't care about a warning light (and I would not) I'd just separate the rear line from the present distro block, plug that port (using an inverted flare plug) and then connect the master up