I think the u-joints are Spicer 1330 series. The link below should help you out.

http://media.spicerparts.com/cfs/files/media/9Mn5KaTiB5f9a6vgJ/J3348-92015%202.pdf?store=original


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