LS1Upgrade

I am in the middle of a LS1 swap into my 02 sliverado 1500. i am working on using the truck wiring harness, and have a question about the LS1 alternator. There are three wires coming out of the alternator, red F terminal, gray T terminal or vice versa to the computer, but also there is a third RED wire out to the starter. If i go with the alt plug from the truck harness there is only the two wire back to the computer. The plugs are both the same and the alternator both have four pins. Does anyone know the need for the RED back to the starter? Or have a charging diagram for the 2000 Corvette LS1? Any idea would be great. Thanks