You'll also need a flywheel remember, not to mention the rest of the clutch and its mechanism.
I have read somewhere in these forums though that the manual and auto drive shafts are of a differnt length, I could be wrong, but before you start it might be an idea to measure the length of your manaul box, and his auto one, from the edge of the bell houseing, to the end of the out put shaft. Also to a spline count, as its possible they may be differnt.