Ok so I am getting a free truck off of my sister. 92 2wd 22re 5spd. I am planning on making it into a solid front 4wd and need to find a build up or some tech articles on this.
I know most peoples reaction to this is just sell it and buy a 4wd and you will be better off.
The reason i'm not doing this is because it has a huge dent in the roof where a tree fell on it and the interior is a mis matched color, the rear glass is missing and the bed is beat up and a differend color from the cab. (by brother in law used it to harvest parts for his own 92 4wd off of it)
It will however run fine once i've changed out the gas (sat for about 4 years and won't start)

I also love a challenge and want a more dedicated hardcore 4 wheeler than my FJ80

 

I went through this with my 91 2wd before I sold it and got my 4x4.

To sum it up...
The 2wd and 4x4 frames are different in the front end. Can't get the front diff, CV, & axles in there. Period.. But you CAN get lift spindles for the front and jack up the back to gain ground clearance. You'll actually have more clearance than a stock 4x4 because you won't have a transfer case hanging down. I very nearly did this until I came accross a great deal on my 4x4.

In all honesty I also had a 2wd Blazer that I took off-road regularly. Couldn't get though as much as a 4x4 but still ALOT of fun. Stay away from the mud and you'll have a blast.

 

If he is doing a SAS, then it wouldn't matter if the front of the frame is different. As long as spring perches and a cross member to mount the T-Case on are possible. You might want to go with a divorced t-case (like one out a Nissan/Datsun 720 4wd)