Steering column connector

Sorry, Redfish gave great info. The key must also switch Accessory power, the draw of which depends on options (stereo, ...). In my 64 & 65 A-body, I installed a relay under-dash for ACC power so the key (in dash, not column) only carries the small coil current. Molex connectors are often used for power, as are "56 terminal". The latter are what is used in your bulkhead connector and many other places (GM also used). This popped up in google
56 SERIES UNSEALED MALE TERMINALS, 56 SERIES UNSEALED, DELPHI/PACKARD TERMINALS & CONNECTORS, CONNECTORS - Terminal Supply Company - Product Catalog
Newer cars use Weatherpack and Metripak connectors.
You can get up to at least 6 terminals in a housing. For more, you may have to use 2 connectors.