63 Dart overheating issue
6 blade fan will probably take care of it after all you have done.
Those 4 blade fans don't really move much air. OK for 70° day, 85° - 90° day not so much.
Had the stock 4 blade fan on this stock '69 318, ran a little warm on the hot days. Switched over to a 6 blade fan and it cooled it back down to the proper operating temperature.
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