If your truck has a temp gage, and it works, keep an eye on the gage. If it has a red temp light, and it works, if it lights while driving pull over, cause you're already too hot.
Make it a point to check the radiator water/coolant level before you drive it, every time, or every day. The lower the level, the easier it'll overheat.
If it gets too hot while driving, and you can't pull over right away, run the heater at full blast. It'll help pull heat from the engine, and I'd rather suffer a little than lose an engine.
If it's a 2.9 and it overheats, it'll likely cause big damage. Baby it until you have the scratch to fix it.
If you replace the water pump, it'd be a good idea to pull the radiator (easier to work on the pump) and flush it really well while it's out.
Good luck!