From your explanation it sounds like whatever is making contact with the #2 plug is hitting at the bend of the side electrode.
Take that plug out and mark the position of the side electrode on the ceramic insulator with a vertical black marker line.
Now put that plug back in and note where the black mark is.
Take out the other 7 plugs and mark them.
Now try the plugs one-by-one until you find one that will put the black mark 180-degrees opposite of what was in the #2 hole before.
Install all the other plugs, fire it up and see if you now have clearance and if it solves your problem.
This is similar to an old racer trick of "indexing" your plugs to put the spark gap in optimal position to fire the fuel mixture.