gm 8.5 differential

I have a 89 cadillac brougham and have noticed noise and vibration from
the rear end. I have removed the axles and found the passenger side
axle worn at the bearing fit. The rear end is a 8.5, 323:1 ration with
30 spline axle fit.
I also found that the cover gaseket to the differential does not have
holes in each side of it to allow oil to flow to the outer bearings in
the axle.
I will need to replace this axle new bearings and seals etc. no big
job. I went to the local GM dealer and they do not seam to know any
thing about the gasket problem. The new gasket now is made smaller but
still partially plugs these 2 oil passage holes.
I have found information on the web stating that this has been a
problem with this axle type for some time and to install a fel-pro
gasket that has the 2 holes made into it.
Please let me know if you have seen the same issue .