These guys are correct, however I replaced a part or two at a time, and that's not bad if you can do it yourself but if you have to pay someone else then definitely do it all at once or the labor costs will be ridiculous because you'll likely have to take the parts of you just replaced to get to the next one that starts leaking. I also failed to use all motorcraft parts, tried to save money with aftermarket but aftermarket cooling system parts for this car are complete crap apparently and mine still overheats a little so I had to buy the parts twice and get motorcraft ones. Guy I bought the car from had replaced a few too but missed the elbow behind the thermostat housing, cracked down the seam, and the hose under the intake.
