Spark Plug Recomendation

[Frustration]

I am helping a friend get his '66 Belvidere tuned up. I am trying to find Autolite 84 spark plugs, and no one seems to have them anymore. The engine is a steel-headed 440. Any suggestions on a good replacement? Thanks in advance.

 

[pnora]

I am helping a friend get his '66 Belvidere tuned up. I am trying to find Autolite 84 spark plugs, and no one seems to have them anymore. The engine is a steel-headed 440. Any suggestions on a good replacement? Thanks in advance.

https://www.rockauto.com/en/partsearch/?mfr=AUTOLITE&partnum=84