Sounds about right Rorii. Go with the GL5 75w90 for the diff. From what i've read here, Redline MT90 is gl4 and should only go in the gearbox.
For the rear diff, whats the difference between 75w90 and 85w90?
I'm starting to read up on oils. This is what I found on other forums. I would like to hear your experience?
True or false? "85w90 is very hard to find and they are non synthetic"
True or false? "In fact the 75w rating will give better
fuel efficiency than the 85w,
that is why more manufacturers are moving to this viscosity
these days as it helps to boost the MPG figures (very slightly)"
True or false? "Synthetic 75W-90 is OK, and should work better than conventional
80W-90 in severe condition and last longer."