I was told there is a second tag or stamping for a big window besides the glove box. I can't seem to find it.
I just did this the other day on the same kind of truck. Thanks to the HAMB. Pass side rail. Top rail. Just in front of the axle. The only other place it is located.
On my '64 F100 the VIN is stamped on the top of the passenger frame rail just ahead of the front axle. Mine also has it listed on the driver door tag, inside on the jamb area.
In addition to the glove box tag there are two stampings - just behind the front axle on the pass side top frame rail AND on the pass side top frame rail under the door (you'll never know that unless you take the body off and carefully clean the frame rail....)
The one I am working on is a big window. But that does not change it VS a standard cab. And my apologies.. it is the pass front rail above the front axle. I have had one off fo the frame before and not seen the other one he ^^ speaks of. But that does not mean it hadn't rusted away!