It will depend on what you intend to do with the truck. If you want to drive it a lot I would recommend a new or good used tank. If your tank is rusted the lining won't fix the rust and eventually it will fail, probably in the middle of the interstate during rush hour.

1953 Chevrolet 3600
Fried Green T'mater (Vern)
In the Stovebolt Gallery
Caution: Political Statement
Man who runs in front of car gets tired, man who runs behind car gets exhausted.