I'm winding back to this post - I finally got around to draining my old trans oil and drained mebbe about 1 quart. The capacity is 5 pints (2.5 qts) per Book O' Info, so hopefully that may help my grinding?!
BTW after self educating that I couldn't find 600W locally, I bought it from
www.ecklers.com They sell it by the quart for 8.49.
And my diff was virtually empty. I siphoned out maybe 2 oz Yikes. Book O' Info shows 4 pint capacity. I'm nervous about overfilling the diff tho', may hold back. Any opinions there?