The 1938 to 1947 tonners have a 5 lug x 6 7/8” bolt pattern. Having researched this for other guys over the years I know that no other vehicle used that bolt pattern on a shallow dished single rear wheel application. So in a nutshell, no other wheels will substitute.
There were two optional widths in 1940. The Ford Green Bible chassis catalog lists them as 11Y 1015B, a 17” x 5” (3.75”) and 11Y 1015A, a 17” x 6” (4.33”). I’ve added the numbers in parentheses because throughout the entire decade of the 1940s Ford failed to adapt to an industry wide change in measurement standards. The National Wheel and Rim Association stopped measuring widths across rim lips in the 1930s and adopted the current system of measurement where width is the space between rim lips. Thus, a 5” became a 3.75”, and a 6” became a 4.33”. Both of these optional wheels were made by the Budd Company. The 3.75” is Budd 41620 and the 4.33” is Budd 41470. Your wheels will have one of the numbers stamped into the metal. Probably on a rear rim lip.
Both these wheels have outer rims made by the Firestone Steel Products Company and sourced to Budd. Using Firestone’s terminology, the design is called the Firestone RH. This rim shared its outer ring design with the Dayton style demountable rims, called the RI. Thus, the RH wheels having the riveted center disc used rings that are labeled RI. Different rings were used on the 3.75” and 4.33”, and they do not interchange.
Safety? This design has gotten an undeserved bad rap. These wheels in their various configurations were an industry standard from the early 1930s well into the 1980s. They have suffered from their association with the Firestone RH-5° (widow maker) that was introduced in 1948 and was itself an industry standard until it was removed from the market in the mid 1970s under recall threat by the NHTSA and IIHS. Today few if any service shops will work on the RH-5°, and fewer and fewer are training techs to work on the RH and related RHP designs. So you may have to look for a shop with an old guy that knows his trade to get tires mounted. I think it’s worth the effort to keep them in service if they are not damaged, heavily rusted, etc.
If you really want to go the route of custom wheels I can go further into it. But for now I’ve rattled on long enough. Stu
Three RH/RI widths:
Note the indents on opposite sides of the ring:
Note the molded identifying info on the inner ring:
