Hello,
If the trans is indeed out of a F-150 It will have a small block bolt pattern. 289/302/351C/351W all have the same bolt pattern. If it came from a '80 to '85 it is most likely a 302/351 trans. If it is out of a 4X4 it will have a short output shaft and adapter tailhousing for a tranfer case as Kountzcobra mentioned. The 429/460 has it's own bolt pattern and the FE series engine has IT'S own bolt pattern.
Thanks Herny (Ford)
--Mike