Many years ago I added one to my '67, and I don't remember doing anything other than removing the master cylinder, bolting on the booster and replacing the master cylinder, the bend the lines around to fit. The bracket may have been part of the booster, and I don't remember fabricating a rod extension (may have been already in the booster), but it would have been simple. Start with ordering a correct booster for you car.
CLICK HERE to have a look at the booster arrangement in the '66 Chassis Manual