Your first picture almost shows the part number under the first row of connections. I went to my storage where the 69 is and measured the opening and it come to 2 3/8 X 2 13/16 roughly. The issue it need to look into is the location of that triangle on the bottom of the bulkhead connector. My firewall opening has the triangle on the side. I'm still researching but your harness may fit a B body.
I'll get back in touch. Thanks Steve
