Is there an overdrive transmission that will fit my 1960 tbird with 352 engine?

There are several over drive transmissions that can be installed. The Tremec 5 speed manuals or the Ford AOD can be adapted. The easiest and perhaps least expensive alternative might be a '67-up C-6 coupled to a Gear Vendors OD unit. All these choices will require some fabrication and are pretty spendy IMO.