1976 Dart Overheating and other issues

Something I noted is with all the green on the fins your rad might be clogged on the outside. Meaning the fins have so much corrosion in them that air cannot efficiently pass to pull heat away.

Also with an a car as mattax mentioned the ac condenser is infront of the rad and it might be clogged up too.

I have seen folks pull an ac condenser and the fins just fall apart into dust just be prepared.