I am owner of a 1962 Skylark conv. cp - a lovely car that has given me much joy and pleasures.BUT - and this really bugs me : When I reach 50 mph the front end shakes as if there is an unbalance in the front wheels. This occurs only at 50 mph. I have tried to balance and balance - with the wheels on or off the car. Tried several rims and different tires. Wheel bearings are new, brakes redone. When I had a NOS idler arm it did change a little for the better. Have any of you out there any experience with maybe a worn steering gear ? (power steering on this car )Ball joints ? Am grateful for input of any kind. Sincerely Knut S