Will a newer T5 Tranny fit a 66 with 289?

[shark7000]

I am getting a 66 coupe with lots of rust, but the engine runs good and the tranny is said to be needing a re-build. Some one totaled our 88 GT convertible, it was parked on the street in front of the house and he crashed into it. I just had the T5 re-built. Will it work in the 66? It's an original 289 w/ 4 speed manual. I just want to use the five speed for fuel economy and the fact it was just re-built, since the 4 speed in the 66 needs to be re-done. I would save the original 4 in case I sold it or something. I would see about getting it re-done too.
Anyway, will it fit?