I own a '74 K5 with 350/TH350/NP203. The guy I bought it from said the 4X4 does not work, but I do not know for sure because it does not run yet. My question is should I rebuild the NP203 or replace it with a NP205. I have read that the NP205 is a better unit, but I would like to know everyone's opinion. If I do decide to rebuild the NP203, were is the best place to buy a kit? Also, were can I find the kit that changes the NP203 from full-time to part-time 4X4? Any information will be very helpful.