We are using an updated HVAC unit in this car and it required some sheet metal work to make it all fit….

Cut a hole in the firewall (this is where the old fan would have popped out)

Fitting better

Made a mount for it

Mount with box out

tunnel was cut a bit too

Remaking the tunnel to fit

had to make a box to cover up the hole…
Start with some cad…

test fit

Then made from metal