I was fortunate to have a couple of pristine '36 Chevy pickups to look at while doing my restoration and also a great VCCA technical advisor, Jim Payne, who provided detailed information. He even had a collection of GM Service Bulletins pertaining to the '36 PU. All of that showed that when the '36 PU left the factory the firewall holes consisted of:
10 1/4" holes for the wire loom brackets and the elongate 4-hole (oil pressure, temperature, throttle cable, choke cable) grommet and rear hood latches.
4 3/32" holes for the VIN plate.
3 larger holes for the vacuum line, dashboard positive electric feed wire from the starter motor switch post and electrolock cable.
All of those holes, along with about 40 others were in my firewall when I got the '36. Now only the 17 original holes are there.
Jim Payne's library of '36 Chevy information was so complete that it included a Service Bulletin on an optional fan shroud that is so rare that in 55 years of owning my '36 and being acutely interested in the '36 Chevy trucks the factory fan shroud on my own '36 is the only one I've ever seen. It took about 40 years of searching to find this one.
