How are u referring to different radiators ? Different year water pumps to radiators yes what did u switch that u didn’t realize would change things. also timing covers for different years can reflects what water pumps are used.
Radiator was original. I had it tanked and tested. I wanted to use the original if possible. The water pump is for a 318 1970. It feeds to the radiator differently on the bottom. We will use 2 to make one hose that will work.