On this topic - the very early GT350 cars had the choke cable AND the amp gauge wires AND the oil pressure line ALL jammed through the "Ford" choke hole in the firewall!
Yes, so thankfully someone figured although it can be done not such a good idea so, about mid -Dec Shelby workers were adding an additional hole to route the amp gauge wires AND the oil pressure line through. (Relevant to the original poster.)
Here are some images of the two versions. First image is a double-digit car, the second and third images are the same car during restoration and is a low 1xx number car - both cars completed at Shelby before the end of December '66. The forth image a later car note the added hole was not always added in the same place - worker prerogative?
On the GT500's this additional hole was not needed since they had electric bi-metallic "automatic" choke an the Ford Choke hole was "open".