What size nuts for 8 ¾?

Does anyone know what size nuts are used to hold the center and axles in place? Do I have to get the mopar restoration repops, or will some grade 8 nyloc nuts do the trick? If so, I would like to pick some up on the way home today if possible…

3/8 fine thread. I have been using old rod nuts for years on these applications when needing an extra.