If it is just a little rusty you can clean and line your existing tank. I saw a write up in a truck mag in the last month or two. Getting it done professional will cost as much or more as a repro tank. I just had a tank cleaned and relined at a radiator shop for an old motor home for 150$. I would have done it myself but the tank was really lacquered up and had baffles that would make it difficult at best.
Mike
