Using 67 cuda dash in a 70 dart

I would lean towards post 3^^ I would NOT mix engine bay and under dash harnesses from differing years. Almost every year has some changes. You will have to re--work the connectors/ wiring going to the cluster. What are you doing about the ignition switch? Keeping the column lock switch?

Yeah I’d rather rework the connectors at the gauge cluster plug than at the firewall plug.

On mine I left the column ignition, but I didn’t use the early dash panel either, just the gauge cluster.