Motorcycle Repair: 92 evo motor vibration, rubber bushings, cylinder problem

Question
I have a 1992 softail with app. 32500 miles. The engine makes a substantional vibration around 3500 rpms. Around 65 mph the vibration starts, and around 70 it tapers off. I know the motor is a rigid mount and was wondering if there is any way to add rubber bushings to reduce the vibration? The vibration seems to be coming up directly through the center of the motorcycle. Its uncomfortable enough that you would definately not want to keep the speed between 65 and 70. Is there any way it could be a cylinder problem. Theres not any noise (pings or tapping) only heavy vibration.  Any advise you could give would be greatly appreciated.  Thank you for your time.
       ERIC

Answer
There is not way to add rubber bushings to your bike. Most all solid mounted harleys vibrate and its usually somthing you have to live with. The vibration is probably coming from the flywheels. The might be slightly out of balance
Good luck and happy riding
Mike