Grigg,
I think the part number is 3680991. The ones I received weren't in their original packages so the part number was from research.
In the Parts and Accessories Catalog, 30 March 1957 they are listed and illustrated on page 509, according to my old notes. In an older version of the book the page number was different.
My 1 Ton has dual rear wheels and if the OP has a single rear wheel truck, the studs will be different.
