[kaptain]

I have not had good results with replacing my radiator. I replaced it in 2017 with one obtained from the original supplier. It lasted two years before leaking slightly at the tube header interface. I replaced that one with a core obtained from Rocore. It lasted three years before developing a similar leak at the tube header interface. 

Thank you for sharing your experiences, Richard.
I am just curious -  I don't know how difficult it is or possible, but have you looked into the leaking spot and thought about manually TIG welding the tube and the header interface instead of replacing the whole radiator unit? Perhaps the tube and the header interface are too thin, too small space to weld?

After watching the video on how radiators are made, I realized welding the soldered joints is nearly impossible. However, radiators are not too hard to rebuild. 
See how people in India rebuild their old radiators. https://www.youtube.com/watch?v=kEwQVUjsQwY