As long as you were not planning on using the tires as a daily driver or any highway driving, I think they may be OK. They probably are not worth very much though. For rolling around the garage, or neighborhood test drives, they would probably be fine.
I would not consider them much of an asset, other than for what I mentioned above. If your truck will not be road worthy for an extended period while you are fixing it up, they might be just what you need. It wouldn't make sense to buy brand new tires now, if you won't be driving it for a a year or more.
