engine wiring

In 1973, you have 3 connectors: engine, lights, wiper and 3 matching harnesses. There is a little overlap, mostly they re-purposed a few cavities in the wiper connector. Check a wiring diagram. Perhaps the 383 was not original, so they had to relocate the spark box (distributor & coil on front in BB/RB engine), which explains the clutter on the driver's inner fender.