[gmachinz]

What is the reason for a 100-amp alternator upgrade? If youre running a lot of interior electrical options Id be highly suspicious of relying on a single 12ga batt feed into the cab via the stock firewall junction-I hope you are upgrading your supply feeds inside as well as outside the truck-Id relocate your common 12V junction to the center of the firewall as a better source to land all of your hot leads. Having said that, a 3-wire GM alternator (CS series for example) is a far better solution than any 1-wire alternator.