The old car price guide for that model shows a #5 condition at #3120. #4 condition $5200. Your truck probably falls in between there somowhere. Rust out in the body is the worst thing. Next is a bad engine. A solid truck that is running & not butchered usually would bring about $4000 but in todays economic climate I really don't know. Everyone trying to sell an old car or truck says it is tough to sell right now. I have had my 58 on the market for several months & have never had a nibble.
