the original harness are 47 years old, they may look good, but they are too old, too much heat, the connections are brittle, and wires are corrouded, you can't see because of the
shielding. the new harness are made in the USA, so if you are looking for a fire, then that's going to happen.
If you value your classic car, you will need a new harness, I work on only classic MOPARS, when I replace my customers wiring harnesses, I cut the old wiring shielding, there is the "green color damage, resulting in high voltage, and de graded wiring