Cut a 1" hole in the firewall for the rescessed cabin heat control pass through. Secured the pass through to the firewall with #5 Avex rivets. Sealed with high temp silicone gasket material. Routed the cabin heat push-pull control to go through the pass through. Cut the control to length and secured the end to the pass through with a firewall cable clamp.
Cabin heat control and paqssage for hot air through the firewall.