Yes, always check the pin vs the master cylinder pushrod hole.
67 Pontiacs got a long pin with a deep master cylinder hole, 68+ got a short pin and shallow master hole. Chevrolet kept the long pin until 1970 for the F&A bodies. this goes for drum and disc.
parts have been mixed over the years, and i'm sure there were factory exceptions too, so always check the master pushrod hole depth vs pushrod length. this goes with manual brakes too. 68+ pontiacs used a short pushrod with retainer, chevy Fbody kept the long pushrod w/o retainer until 1970.