You have a Motorcraft 2G series alternator. It has a D shaped voltage regulator plug rectangular-shaped power plug, these are the battery wires that go to your alternator. You can't upgrade the alternator over 80 Amps. The power plug uses two small of spade terminals, which may overheat and catch fire. My advice is to upgrade to the 3G series large case alternator, because the D shaped regulator plug fits, but you need to cut off the square power plug and replace it with two heavy duty ring terminals. Ford changed to a regular battery stud because of problems with the rectangular power plug. The 3G large case alternator starts at 150 amps and may go up to 250 amps. Here's a link
http://alternatorparts.com/Ford_3G.htm I recommend the 3G 160 amp alternator with the heavy duty rectifier, part # F1-3G-HD160.