Flux drive cup o-rings

[_dV]

I've noticed in the Flux manual that there are supposed to be o-rings ( part 75080) in the diff drive cups but there were never any in there.

The manual for the suspension conversion kit i just received also shows them. Although it lists them as part 6811 which is a smaller o-ring that normally seals the diff cup.

I'm not sure what they would be for but my truck hasn't had any issues without them. Anybody else got these o-rings in the diff drive cups?