1st gen throttle cable question

[streetk14]

I am converting the stock throttle linkage in my '68 to a cable style so it will work with my new LS1. I bought a complete 6 cylinder/crossram accelerator pedal that bolted right in. My question is: Do I need to drill a new hole in the firewall for the cable to pass through? I don't see anything that lines up with the rod that comes off the pedal.
-Andy

[streetk14]

Today I took a look at my friend's '68 Firebird which has a factory cable system. It looks like the hole for the cable to pass through was only drilled on the cable cars. Mine doesn't have the hole, so I will need to make one.
-Andy