Bolt pattern will be wrong, ford used a different pattern. The only GM application I know of for this trans was some Pontiacs used it in the mid '60s. A better choice for an overdrive would be to find an SM 318 or 326 with the Borg-Warner overdrive. Those are a direct bolt in (the 326 is slightly longer). The overdrive unit has to be used with it's companion trans, though, as there are differences in the case and mainshaft to allow for the overdrive.
Other options include the T5 and the GM version fo the A883 (M86Y) trans. Those are both floor shift.
