This is a change to the builer's manual. Bolts that protrude through the firewall are no longer used to hold the flute tubes and rudder pullys. Counter sinking #10 screws make firewall installation much easier. My firewall will have 6 holes without rivets because of this change. No big deal, I can access the screw heads fome the engine compartment if I ever need to do so.
Counter sink firewall flang nuts that support the Flute Tubes and the Rudder cable pullys.
