If any of your collection of connector links are KMC links for KMC chains, they might have a number on the side plates that corresponds to a pin length. And if so, you can look that up to see which type of chain. Note that KMC has two different links for eight speed chains with different pin lengths, 7.1mm and 7.3mm. So, be careful in mixing eight speed parts.
https://www.kmcchain.com/en/series/chain-connector-12s-11s-10s-9s-8s-7s-6s-speedI once read somewhere that Shimano and Sram use different widths on eight speed, but I do not recall which was which.
