With that in consideration, I searched online and found that both Classic Industries and that Classy Chev both claim to have a bit of hose that would fit the application.
When I looked up under the dash I saw a bit of metal tubing coming off the underside of the cowl vent area that pointed directly at the hole through the firewall that is behind that metal deflector visible just above the valve cover (circled in the photo in the original post).
It looks as though the design is for the water to go from the cowl vent drain into a piece of hose through the firewall and then drip down the drivers side of the engine.
I have attached a photo that shows the alignment of the cowl vent drain deflector (my term for it) over the driver's side of the engine. I am not going to stress about it too much, but it seems surprising that the design doesn't have the hose carry the water farther down toward the ground.
Nick 1940 KC Model 1/2 Ton Pickup Project (with '37-'39 Bed and what we think is a '42-'46 Frame) Taos, New Mexico
