There are often questions about how to identify the 1932, 1933, and 1934 Model B, BB, and Model 46 Pickup cabs. The cabs were similar but different each year. The major differences relate primarily to firewalls, back panels, and fuel tanks.
Pictured above is the 1932 Model B and BB truck cab. The most distinguishing feature of this cab is that it uses the same separate firewall as the Model B cars. The separate firewall design is used only on 1932 cabs.
Pictured above is the 1933 and 1934 style Model BB and Model 46 cab with the integral welded firewall. This firewall is not removable, and is unique to truck cabs.
The pic above shows the back panel of a 1932 cab, which was also similar to 1933. Contrast this with the next pic of a 1934 back panel.
The last pic above shows the 1934 cab backpanel. For 1934, Ford added another wide reveal molding shape above the previous moldings in the back panel stamping. This was done to stiffen the back panel and reduce noise and drumming.