Yep understand the issue, you should see the wiring in my 81 firebird, previous "mechanic" spliced in cut up orange extension cord and part of a jumper cable. Blown engine so it's still in storage. Previous ... replaced the v6 with a V8 and yeah it's a mess.
I hope I don't over burden you, but it's really simple.
Pink wire goes to positive Batt on the HEI and is key switched and should be on in start and run, off during light test.
The earlier system the HEI is energized at "start" by wire from starter solenoid as 12 volts full, and the HEI stays running from key switched power in "run" but has resistor in-line, factory used a resistor wire.
Yours should just be the pink wire.
For the Alternator, energize it separately after the engine starts and is running, and is same for the electric choke.
As previously stated by RabbitHoleSS, #1 or the "I" on the Alternator energizes the internal regulator and initiates the process of charging. The #2 is the "sense" wire and runs all the way the junction on the starter, but normally you don't need this. The idea was that this location was the farthest from the battery and accounting for voltage drop this would give you a more accurate "sensing" of current electrical needs.
Just do as suggested and bridge that input to the large post coming out of the alternator. Use a 10 gauge wire. You only need short piece. The post coming out of the alternator is the "output" and a 4 gauge wire should be fine. Connect the post of back of alternator to the battery and 4 gauge should be fine.
You will need the bigger yellow crimp connectors. Make sure to use the yellow ring connectors that fit the post properly. Don't use the rings that are too big for the post. Not only is this sloppy and doesn't look professional, but electrically it makes for poor transfer of the electricity. Depending on your basic environment you might want to use the electrical shrink wrap, especially if a daily driver where rain or snow is common.
