Firewall question

I am assembling the firewall.

The drawings show F-801L on the engine side of the firewall. The plans state the firewall is back drilled thru the backing plate for the inflight adjustable rudder pedals. I am using ground adjustable pedals.

It is not clear to me whether the backing plate is omitted when using the ground adjustable pedals. The F-801L does tie together the reinforcement angles on the back of the firewall.

Are these backing plates used with ground adjustable pedals?

I have the ground adjustable pedals too. My F-801H-L/R-1's overlap and rivet to the horizontal reinforcement angle with no F-801L's.