Truck
Sounds like my Eurovan. Keep the truck. A new car will eat your lunch in insurance and registration costs, never mind payments, and the only reason I can see for getting one would be the reason I got a van--room for the extra kids. If you're just getting another work truck, what's the point? When you have a work truck, you WANT a beater. You want to worry about scratching up the bed of a shiny new truck with cinderblocks or something? If you must get a new one, keep the old one. You won't get five cents for trade-in anyway.
Saw a really great "King of the Hill" on this subject.