Like I said, the 5-speed bell housings are different. Same bolt pattern, but they use a different flywheel so the starter position is slightly off. The T-5 transmission will work just fine with a 5.0L bell housing.
I don't know anything about autos, but now that you mention it I do recall the v-6 4r70 being a popular swap into our cars. I don't know the details on the swap though.