Need some electrical help with my ‘68 Plymouth Valiant 100

Dana67Dart said
The factory service manual has all that info.

View attachment 1716335336

I can not speak to the accuracy of the site but it's a start

Spark plug cross reference

Thank you, the issue is the previous owner put in a 4 barrel edelbrock carb, so I don’t know if these spark plugs would necessarily still be a good fit or not.