'67 C10 Antenna Question

[JoeMamma]

Hi,

I just picked up a '67 C10 that was not equipped with a factory radio. The antenna mounting hole on the top/right side of the fresh air cowl is not drilled out. I also don't know where to pass the antenna cable through body sheetmetal and into the passenger compartment. I pulled the glovebox and couldn't find any existing holes or rubber grommets on either the firewall, the air cowl or the door pillar.

Could someone take a measurement of their own antenna base and let me know where to drill the fresh air cowl? Any idea where the cable enters the passenger compartment?

Thanks,

JoeMamma