I found this article about the 9ft beds, mostly as they relate to the featured 1946 1.5.
The attachment is a screenshot of some fender info*
*So an argument could be made to install 37-38 fenders (standard width) on my truck, even though I'm planning on running single tires in the rear
Here's the entire article...
http://oldchevytrucks.com/blog/index.php/2015/03/1947-chevrolet-1-12-ton-pickup-open-express/