8-3/4 Noise After Rebuild..What's Normal??

Did you check the wear pattern when you installed the gears? At what speeds are you cornering? If it is above 30 mph or so, I do not think the noise would be the sure grip. The sure grip would not cause the noise when going straight either. If your cornering noise is at slow speeds then maybe friction modifier will help that. If it at higher speeds then maybe an axle bearing noise since corning puts more weight on the outside bearing, sometimes making it louder if the bearing is rough. As far as the noise on accel and decel, it sounds like gear noise since it is quiet on transition between coast and cruise. I have installed a couple of dozens of gears of different brands over the years and have never seen a gear set get quieter after brake in. If they are noisey when installed then they stay noisey. EVERYBODY manufactor of gears will have some noiser than others. I once while checking out a brand new Ford pickup with 2 miles on it, found very loud gear noise on decel only. Changed gear set and all was quiet. If you could not get a good wear pattern when setting your gears up, I would try another gear set. If two gear sets will not have a good pattern then you should get another case. I hope this helps, Ray