I checked the 69 factory manual [sect. 2] and they show the bushing [aka body vibration dampener], but there's no torque spec. I also have a Fisher body manual and there's nada in that too. There is a spec for full-size cars which is 25-40 ft./lbs., but that's a full frame not a uni-body.

I'd bet Pontiac didn't expect there cars to be around 45 years later and the bushings where suppose to last the life of the car.

I just replaced my body bushings with delrin bushings and the install instructions listed 150 ft./lbs. This seems accurate considering the size of the grade-8 bolt. The original bolts required < 60 ft/lbs when removed, so I'm not sure if they were loose after 45 years or ?