LS Swap Alternator wiring
 

For those who have gone the standalone harness route (Gen4 LS3), how did you go about integrating the stock '70's alternator harness wires?
I'm trying to decipher the factory diagram, and the 10si alternator has the 2 wires going to the plastic connector, and the "charge" wire going to the alternator stud.
These all somehow tie into a wire leading to the firewall junction block which also ties in down to the factory starter.
Trying to make sense of it all and how I can simplify and/or delete all of this.

This is on a 77 C10 with factory gauges and a factory voltmeter