Grounding questions.

Typically on these old girls there is one ground from battery negative to core support, one from battery negative to driver side head and one from passenger side head to firewall.

The reason for grounding is to ground where electrical impulses are happening, which is mostly in the heads (think spark plugs). Grounding to the firewall covers the cabin, grounding to core support is because of lights. Block would be grounded through the head bolts.

That's my theory anyway. I'm sure if my theory is wrong, someone will correct me, lol.