What’s this hole for?

[blown motor]

74 Challenger firewall. The hole is dimpled inward. Just wondering what it was for.

[jimynick]

That's the hole we used to use to run a wee hose from the whisky filled w/w container to a carefully clamped, concealed and aimed hose end under the dash, so when you hit the w/washer you got a nice shot dispensed. Didn't everybody? Don't forget the Coke! 

[MoparLeo]

This is all of the pictures that I have in my files.

[anlauto]

Must be a 74 only thing 

[Bullitt-]

 I see plenty of photos on the WWW of '74s with the hole but never anything in it.
         It's known the b-bodies shared the firewall with e-bodies.
The b-body had fender braces that anchored to the spot where your mystery hole is.
        My theory is they added the hole to all stampings. 

   '74 Charger pic for reference

[7E-Bodies]

So B bodies and E bodies used the same firewall? I've just learned something. Many more to go of course. 

[blown motor]

That could be it @Bullitt-  I also didn't know b and e bodies shared the firewall.

[anlauto]

 

[Brads70]

I didn't know that either Wade! Thanks learned something new!

[Bullitt-]

So B bodies and E bodies used the same firewall? I've just learned something. Many more to go of course. 

That could be it @Bullitt-  I also didn't know b and e bodies shared the firewall.

I didn't know that either Wade! Thanks learned something new!

  inner fenders and associated items as well on the 71-72 b-body
https://www.rosevillemoparts.com/product/inner-fender-panel-kit-right-70-74-e_body-71_72-b_body/

[PLY474]

Looking through my 74 photo collection, not every car got the firewall hole.  Here are 3 examples without it.  My car did get it.   

[PLY474]

In 73 a capacitor was mounted in that location.  For what, I'm not sure.  Radio?