Triumph Repair: Brake master cylinder, brake master cylinder, dual circuit

Question
I have a 1970 GT6+, and am wondering what kind of brake master cylinder goes in it.  All the pictures I have found on google, show a single line brake, but my car has a pressure warning switch, which was supposedly only used on dual line systems.  Please help me make this car a beauty.

Answer
Hi Justin,
There was a single circuit master cylinder used on a GT-6 but only on the models that had a remote brake booster/master cylinder system. If you don't have a remote brake booster then you should use the dual circuit master cylinder. With the dual circuit master cylinder you will not have a remote booster.
Howard