91 Vibratinos

I have a 91 bonneville on which i just got the rear brakes replaced after cracking the shoe and destroing the drum on the right side. It now has a vibration that shakes the car at 55 and up and its especialy bad at 65 mph. The place had orignaly thought it was the ball join that was broken. (shatterd really) but that seems to have made little differnce. There is also a vibration throug the pedal which they think might becausue of the bad kinks in the flex hose from the front breaks. (the front breaks are brand new also). So any sugjestions about this would be great so I can drive my car with out feeling like im in a paint shaker again.
thanks
-C

When is the vibration felt? Braking, coasting, accelerating, other??

Many things can cause a vibration. Basically anything that turns while you drive.