Overheating dodge ram 1500 extended cab.

OK,  so my boyfriend isn't really a mechanic
person but he's also learn for his truck's sake.  But
before all this happened it was just the radiator
that was acting out.  But we fixed that.  The main
problem now is how it over heats while driving.  I
have to watch the temp in the water pump.  He
said once it gets to 200 that's bad.  But 260 I'd
have to sit somewhere for an hour to let it cool off.  
My big question here what really is the main
issues?