I would beware..10-bolt positive-traction rear axles were rare unless the car is an SS, especially with 3.08s. '69s had the 8.2" ring gear and the car may have a later-model 10-bolt swapped in. The later 10-bolt is a good thing unless you want originality. To add power brakes all you have to do is put a booster behind the master cylinder. My 2 cents and hope this helps.