Jeep: 4wd conversion, jeep cherokee, vacuum lines

Question
I have a 1991 Jeep Cherokee. Ihave done a lot of modification to it (engine and Body).There is just one problem however, it isnt 4wd. i love the jeep so much that i would rather convert it to 4wd than sell it and buy one. my question is will a transfer case bolt on to the automatic transmission that is in the 2wd 4.0 Ho, or do i need a completely different transmision. any other info on this project such as vacuum lines or axles would be greatly appreciated.

                         thanx
                           randy powell  

Answer
Four wheel drive and two wheel drive transmissions have different mainshafts and one has a tail housing and the other does not.  Converting from two to four wheel drive is quite a job but made easier if you have a doner vehicle to take parts from. You will need a lot of them.