69-88 is good. Even the early brakes ("M" calipers) will be quite good enough for almost any 914. M calipers are steel and have a 3" spacing between the caliper mounting bolts.
The "S" calipers became available at some point in there, and they are supposed to be better. They are aluminum, and have a 3.5" spacing between the mounting bolts.
In 78-80, the "A" calipers became available. These were larger than the S calipers, were made of steel, and also used the 3.5" bolt spacing. In 84, the Carrera used the same brakes but with a slightly thicker rotor (and therefore thinner pad).
The A-caliper brakes, in either SC or Carrera incarnation, should be more than enough for any 914 that is actually street-driven.
--DD
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Pelican Parts 914 Tech Support
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