'69 Cutlass, just above the gas pedal and the 2 small openings for the throttle and trnsmission cables, is a hole about 2'' in diameter, looks like something was in there.....also it appears to be a factory hole , cause there is even a matching hole in the pad ,,, I don't remember any thing there..........

 

I recall there being a big hole for the A/C wiring and vacuum hoses...

 

that makes sense, cuz , 15 years back when I got this car the previous owner was starting to put in AC, and had some of stuff already installed, and for some reason, when I bought it, I took out what he had put in .........thanks

 

I bet that is the hole, as it is a big one, even though the wiring and hose are quite small..

 

Depending on the exact location of the hole, I question the possibility of it being the pass-through for the push rod for a manual transmission equipped car. It's hard to truly decipher without a pic or blueprint. Air conditioning? Eh---Unlikely.... Good luck and have a Great New Year!!
Heath

 

I was a little off on the excact location of the hole.... it is a 2'' hole in between the gas pedal mount or pivot hinge and the 2 small square holes for the throttle cables

 

The rod from the clutch pedal goes through the same large opening in the firewall for the steering column.
The only firewall hole around the area described that's shown in the assembly manual is just above and inboard of the throttle cable and downshift cable opening and it's for the AC wiring and vac hose. The manual doesn't show any holes between the accelerator pedal mount and the the throttle and downshift cable holes?