What connects the A/C floor vent to fan box

[71convert]

I am restoring my A/C heater system in my 1971 convertible and I'm not sure what attaches the bracket on the floor vent to the fan box (see pic below - circled in red). When I took my unit out of my car there was no screw or clip connecting them together. It was just flapping in the breeze. Thanks.

 

[Hemikiller]

It's a little plastic epanding push clip, like the used on modern cars for body parts. Ford # is 380464-S

 

[71convert]

Thanks Hemikiller!

 

[rio1856]

https://secure.cougarpartscatalog.c...-mercury-cougar-/-1967-1973-ford-mustang.html

 

[71convert]

Thanks Rio!