Need help to identify years

My name is Matt and I am in charge of new product development at Champion Cooling. We have a new 19inch Radiator that was developed using a 64 Dart Radiator. The Customer has not sent us any info about the car, can anybody identify what other years it will fit and what engine configuration. Our Industry "Radiator Cross Referance Catalog" Does not go back this far. Any help for other years this will fit would be much appreciated!
Thanks
Matt
Champion Cooling