04 PreRunner 2WD to 4WD?

Okay I've got an 04 PreRunner SR5 that's 2WD automatic and the 3.4L. I've been looking around trying to find a recently junked one to rip the parts off of to convert to 4WD without any luck.

First off: Is it even possible to take the parts from another truck and just bolt/weld them on, and if so, which model trucks?

Secondly: Is it cost effective to do it that way?

 

Yes, 96-04 tacomas and i think its 96-02 4runners.

Here is my build, it has most everything you will need, or at least your key items. Everything is bolt on.
http://www.tacomaworld.com/forum/1st-gen-builds/153323-4x4-wanna-come-true.html

I stayed with the 2000 and back because I wanted manual hubs.

 

Check out TTORA as well.