OK now that we worked out what we got heres what I think about the seal (on a 9" modified):
I WOULD use one! I can see where the "sealed bearing" would "mostly" hold the
oil in the "tube" and would not leak. BUT I would be concerned about the rear end
oil up against the side of the sealed bearing and possibly "weakening" the side seal on the bearing? OR,
oil getting past the side seal and mixing with the "grease" inside the sealed bearing.
In short, yes I WOULD use the seal.
Ernie