Mazda Repair: Start shaking from the front at 65 mph., mazda miata, dynamic dampers

Question
My 1990 Mazda Miata starts shaking once I get to 65 miles per hour.  I would like to know why is this happening.  I balanced the tires and changed the shocks.  I did not change the springs, but I did not think this would be causing the problem.  Can you please tell why is this happening?  

Answer
Well I know for a fact that on some 626 models and MX-6 models and some other Mazda vehicles there has been many complaints of abnormal vibrations they can feel throughout the car. One thing that you might want to check is for wrongfully positioned radiator dynamic dampers. If the dampers are seated wrong you can fix that problem by: removing the upper radiator mounts then gently pull the radiator upwards which should free the dynamic dampers from the body. Remove the dampers from the radiator and place them correctly back into the body holes which should tell you if the dampers are flush and seated right. Keep the radiator level and simultaneously insert the lower radiator pins into the holes of the dampers and gently push down the radiator until it is fully seated in the dampers. If you do this procedure and the problem still does not go away then contact me again and let me know. My Mazda did the same thing and the vibrations could only really be felt at speeds of 60-80 mph. Feel free to contact me any time. Oh some other things that might be causing the vibrations are: worn or loose front hub or wheel bearings, worn tie- rod ends, worn lower balljoints, and a worn or broken CV joint.