Chad,

Last night I did an inventory on all of the steering boxes I have. It turns out that only the 1940-41 trucks had a vented fill plug.

[img]http://www.surfacezero.com/g503/data/3176/2013-12-22_14_26_34.jpg[/img]

[img]http://www.surfacezero.com/g503/data/3176/2013-12-22_14_25_59.jpg[/img]

I think you are good to go with your "new" model truck.

Paul


1941 Chevy 1 1/2-ton WW2 4x4 dump truck
In the Stovebolt Gallery
Lots more pictures