It holds 0.7 quarts. It is impossible to overfill, but quite tricky to fill at all!
I put Redline 75/90NS in the tranny and 75/90 in the rear differential a couple of weeks ago. So far no grinding! Deceleration noise is still there, although it's not too noticeable if I keep 3-4 more pounds of air pressure in my front tires than in the back.