N12y I believe is what ma Chrysler used, ngk has r5671a 7. It is a 14 mm 3/4 reach non resistor but uses a 5/8 instead of a 13/16 socket. Easier to remove that's all. At 3 bucks a pop jegs has them in stock.
Let it bring up the spark plug link for the 58 New Yorker and it gives several resistor and non resistor plugs https://www.rockauto.com/en/catalog...4l+392cid+v8,1327867,ignition,spark+plug,7212