That's pretty strange that they have 2 separate PNs for the same exact bolt. Generally(having worked in Ford's parts department), Ford will send a package of smaller parts such as bolts, nuts, washers, o-rings, etc in one package, and Ford can sell them separately.
Same thing goes for some spark plug manufacturers. They sell their plugs in packages of 4 or 8, but you have the option to buy 6, or just 1 for that matter.
Mark
