Just bought a 1983. Sunrader 18ft It's in really bad shape inside. Motor has only fifty-eight thousand miles. I worked in the RV business. And Elkhart, Indiana for 30 years I live in Tennessee now. I have 7 Toyota trucks. From the 80s This is my first encounter with one of these are very hard to find here. It still has the five lug on the back. I am thinking about taking 1983 four-wheel drive frame and start getting it ready. To throw the six lug axle on the back Can anyone tell me? Did they do modifications to add the four-wheel drive? Or was it just a regular 4 wheel drive frame?