the 2 wheel drive versions of the mj, xj, zj, and wj share the same unibody with the 4 wheel versions and the non drive front axle mount the same way as the for wheel drive axle, so for the most part it is a bolt in affair to convert a 2 wheel drive to a 4 wheel drive. it is generally the best if you can have the donor vehicle to get all the little parts from. but the minimun you need are the tranny, transfercase, front axle, both driveshafts and the all the hardware that goes with it. i am sure someone has done a right up about it somewhere.. just do your research before you start.