Agree, but what I do on everything is coat gaskets with hi temp never seize, I have found it works great and gaskets peel off, no scraping.
I would suggest driving the car for 5-10 miles and get the rear warm to hot before draining, don't drain it cold, and inspect the fluid for metal, a lot of grounds would not be good, some shavings are normal, check the gears while you're open, mine ran fine and no noise and I found a pretty good size chip missing from my pinion gear and it became a complete rebuild, it actually started with an axle bearing started to weep and morphed into a complete tear out to a shop, had them put in an Eaton posi unit, tougher than stock and no one knows by looking.