2 litre conversion

I have myself a 2litre motor to replace my 1600 it came with (I hope) all the bits and pieces. As it is out of a mk3 it has a 2 piece tail shaft with it the questions are

Is it possible to use the mk3 tail shaft & how would it anchor to the bottom or is the original shaft able to be used

also is there a thread on this I have looked but can't find any thing