The balancer doesn't appear to wobble. Yes the motor was rebuilt by a previous owner approx 2500 miles on it. I was told it has a 6 pack cam, bored just 20 over, and the vibration was noticeable when I bought it. I wasn't given much info on the rebuild itself. I realize it is hard to diagnose these issues without having the car in front of you, so I appreciate all your efforts.