There are two disc brake setups for 1967, the early has the proportioning valve located at the rear near the flex hose to axle bracket, later versions had the proportioning valve looping around the distribution block/master cylinder to more accurately indicate a loss of pressure (fluid) in the system. Although almost identical to the 68 style, the 67 distribution block/master cylinder is very rare in its mounting arrangement. I think the change-over was made in February, March or April. The latter system was continued into 1970 at least. That's two different lines to the rear for disc alone, maybe a third for drum.
Jim