I have a 1966 T_Bird and have just had the tranny rebuilt. Now when I am going around 45-50 mph, the car has a vibration. Is this a problem with the tranny or is it the tires?
Also, My turn signal keeps blowing the fuse whenever it is activated. Does this mean there is a short somewhere or is it just the flasher?
Thanks in advance.

Sounds like the driveshaft was incorrectly reinstalled and is not in balance, but could be something else in the trans. or a wheel out of balance or bad alignment. If the fuse keeps blowing - first look for a crossed double filament bulb in the circuit. Then look at the rest. Flasher is unlikely as a suspect unless it's the original one that came with the car.