I would do the small hose from water pump to block. I don't think it can be replaced without removing the pump. I would also do upper and lower radiator hoses and thermostat. Be careful of upper hose connection to radiator. If there is not a metal sleeve inside the plastic connection to the radiator it means it is an old radiator. They tend to crack there. Also new serpentine belt and check belt tensioner. They have to come out so if they are old replace them with new. I think I got my water pump from dealer and it was not 500. I don't remember but I think 200+. Make sure you use mb antifreeze. It doesn't mix with others