HOw can I tell if my 1957 T-Bird has the rare overdrive transmission option?
There will be a black lever just to the right of the steering column mounted to the lower dash plate that will say overdrive on it, you will push it in for overdrive. If it's not there then you don't have it.
Search Ford Thunderbird Questions
Are you a UK consumer? CarGurus now has a discussion forum in the UK.
Ford Thunderbird Experts