Ok you'll need a terminal for 12 gauge wire then. You can fit two 16 or18 gauge wires into the crimp. Napa sells the terminals. They were known as Packard 56 way back in the day, lately called GM Spades. As for getting the correct plastic connector, check Totally Auto. They are a sponsor here on Moparts. I've bought used connectors from them.
I had posted about rewiring a '70 B body, listing parts and tools used at the link below. You may find some useful info there.
https://board.moparts.org/ubbthreads/ubbt...tml#Post1672042This is where I bought my terminals. You have to buy in bulk from them though, I think the minimum order is $20.
http://terminalsupplyco.com/Store/Default.aspx?CAT=DEL010&PCAT=54228#Categories
