I was wondering if there is a huge difference in information between the body and chasis manuel for 1975-1980 and the 1980-1984 manuel? In the specter catalog there is a huge differnce in cost. I am only asking because I have the 75-80 manuel, but picked up an 83 fj40 and am wondering if it is worth getting the newer manuel. I guess I am wondering were is the beef.