Looking at Engine bay wiring harnesses. Have to walk through the 64 vs 65 Valiant wiring diagrams to see what's maybe different. CI has a 65 SB ECU harness in stock
Very different connections at the bulkhead. Also '65 introduced the fusible link IIRC.
Then there's the mystery of the Canadian variations which did some things differently, like that starter. That uses a remote solenoid IIRC