It's an 8-3/4" unit. I did not rebuilt it, I purchased it brand new. I have been using valvoline 80-90 gear oil with Ford Motorsport friction modifier. There has been friction modifier in the rear end since the S-G unit was new.

As far as the spider pinions.... I have not yet removed the center section, so I have no idea. I did check and adjust the axle endplay this past summer. Didn't seem to have any effect.

So it sounds as though there is no way to loosen the preload that is on the clutchpack (??). I suppose I'll just dive into it and see what I find. Any other suggestions?