You're forgetting carb heat
Hi Charles,
The F-746 is set up for Carb heat, throttle, mixture, prop.
Change it as you see fit for your situation. I placed flap switch in the carb heat spot since I am injected.
The cabin heat valve is actuated by a bowden cable that passes through the 3/4" angle on the firewall just below the firewall recess. The cabin heat control will naturally want to be somewhere on lower right side of the panel in order to execute the simple cable arc between actuator handle and heat valve.