I thought someone might be interested in seeing whats under the tape! I am going to modify the engine wiring so I started stripping off the factory tape. This is a 67 with a 340. What you can see here is the OEM splice/connection for the red power wire from the starter (coming in from the left) and the red alternator charging wire (with the black cap) connected to 3 red power wires headed for the firewall connectors. This was covered with another layer of tape under the harness tape which is the burned black stuff under it. Also in the picture is the resister wire coming from the firewall connector(tan with woven insulation) connected to the red wire going to the coil with the yellow wire from the starter. Both connections appear to be soldered.
I saw similar splicing in my old harness, not sure if my was stock though. I skipped the fusible links and put a fusebox by the battery, so far very pleased with that: https://www.v8buick.com/index.php?threads/fusible-link-what-to-do.383521/page-2