They are the same size but ford also fitted a physically smaller 55amp one fitted to some European sierras, but generally the alternators will be sided and you can swap the pulleys about fairly easily

Just make sure that you have lugs in the correct places, there is normally one that has the bolt through it with another boot for the adjustment, I've seen only on with a toothed wheel adjuster, everything else is either fixed with an adjustable tensioner for the serpentine application or you have to get there with a big lever to put the tension on