It is this type of connector:
https://www.amazon.com/dp/B001RPPRXC/
or
https://www.summitracing.com/parts/pco-5665pt
or this listing is interesting because it gives a list of exactly what parts were used to assemble the pigtail. It makes me wonder if he would assemble one for you with your choice of wire length.
https://www.ebay.com/itm/132363680772
If you also need the wire and cloth jacket used for heat protection as it normally lays on the engine,
https://www.americanautowire.com/sho...ire-repair-kit
I'm needing to re-do my wire and deciding what exactly to get.