I have a technical question I’m hoping for some help with. I have a 68 convertible that it’s back on the road after 31 years. The car has 42,000 original miles. I’m experiencing vibration and shaking between 40 and 45 mph and intermittently at other speeds. I’ve had the wheels balanced and I put new upper and lower ball joints and tie rods on both sides. I’ve got an appointment to get the front end aligned the first of this week. Anybody have any ideas about why I might be having this problem? The car has new radial tires and used 15 inch Rally 2 wheels. Thanks