Spark plug question

N10Y is what they called for back in the days, along with the 426 Hemi. I have a couple old Champion books. Now a days they just say everything needs the RN12Y. I have picked up a couple sets at swap meets over the years, along with all the other plugs the 340, 383, and 440 used. These are all NOS and made in the USA. I don't think they make them anymore. But do some searching.