I am looking to convert a 19" radiator to a 26" in a 1970 Challenger. I have had several suggestions offered to make this happen and yet still not sure how to proceed. Ultimately, I would like this to look stock and not hacked up or converted.

Several individuals say I need the 22" conversion panel only (left panel), another mentions that both left and right radiator support panels need to be replaced and yet another says only a complete support assembly repalcement will work.
Has anyone done this type of conversion correctly and if so are you willing to share the process?
Thanks