Would all base Dash harness for 70-72 be the same? or are there specific harness for ac cars perhaps? or something else? It seems most options can plug into existing connectors.

 

Your best bet would be check with M&H Fabricators Technical Support (562) 926-9562

they build direct-copy reproduction harnesses right from oem blueprints so they'd know.

 

There are unfortunately minor differences from year-to-year. For example, the 1972 harnesses have the wiring for the FASTEN SEATBELTS light (on cars built after Jan 1). Also, there are sometimes differences in the wire locations in the firewall connector. I found this out the hard way.