If you're planning the big right thrust experiment, and you're using a nose ring, you'll be needin to have the mount to firewall blind nuts mounted on a separate plate, free from the firewall and cut horizontal slots in the firewall instead of holes. As you add right thrust you'll need to progressively offset the mount in the opposite direction.
You'd be surprized that 1deg' extra originating from the prop hub is considerable offset by the time it reaches the firewall.
Make sense?... I'm in doubt myself[]
Hopefully, Somebody else will explain.