Well since you already have an np205 t-case the only thing left to do is to replace the auto matic front hubs with a pair of normal lock-out hubs. Then you will have a true-part time 4x4 system.

Yes it's worth doing because with lock-outs you can un-lock them when on the street and save wear on you front axles, gears, tires, and bearings==save fuel too!!