I've ran the Autolite AR3993 and NGK R5671A-9 with success.

I prefer the NGK nowadays as Autolite QC isnt what it once was. I chased an random miss for a couple of races in 2021 - turned out to be a bad new plug.

33 Plymouth Roadster - 383 - 5.90 1/8th 9.58 1/4
68 Dart - 340
66 Belvedere - 400

Windy Hollow Garage - https://www.youtube.com/@windyhollowgarage