Hello Rufus , well the differential is working good , but i got to beware for some hidden things that leave me doubt also these days . It's a bit long story and i don't know if you know it completely . 
I will try a brief for you :  The lsd case is little bigger as supposed and do not fit perfect . 
What i found wrong : the lsd case spin against the pinion input bearing seat . This wall needs to be grinded a lot to fit . 
Why you need to grind a lot : because when you need to do backleash you need to move left/right . and without grinding this  move is forbidden . 
What is going wrong right now : I grind as much as i can the outside of "pinion bearing seat " to have some distance  and at least .005 freespace between lsd and axle case , at the end of correct backeash . 
I haven't care about  friction between one spinning thing too close at wall , this action have grind more from that seat . I look at it after a couple of year and i sow   bearing partially  exposed . 
One day i will have a big failure on that 8 inch just because the pinion seat will not be anymore and bearing will not have anyting to stay in place .  that will be a big bang . 
If you have just order it , you are still in time to send it back and buy a different brand . 
For all the gold i will NEVER suggest anyone to buy that one " power grip pro " unless they modifed the case size .  
hope is all clear , you can ask anytime ! 
alex
 

That pocket bearing bore is where I've seen EVERY 9" case fail I've ever seen fail.  Grinding in that area is super sketchy.  The reason for the failure is a design flaw.  The pinion bearings on the 9" (and 8") are too close together, so Ford added a 3rd pinion bearing for extra support.  I will say using a solid pinion spacer does seem to prevent case failure.  The crush sleeve can oscillate back and forth under hard loading and let the main pinion bearings get cockeyed in the pinion support, which puts an enormous load on the pocket bearing and fractures the case blowing that little semi circle of iron off.  A solid spacer doesn't oscillate. 

TKOPerformance wrote:

That pocket bearing bore is where I've seen EVERY 9" case fail I've ever seen fail.  Grinding in that area is super sketchy.  The reason for the failure is a design flaw.  The pinion bearings on the 9" (and 8") are too close together, so Ford added a 3rd pinion bearing for extra support.  I will say using a solid pinion spacer does seem to prevent case failure.  The crush sleeve can oscillate back and forth under hard loading and let the main pinion bearings get cockeyed in the pinion support, which puts an enormous load on the pocket bearing and fractures the case blowing that little semi circle of iron off.  A solid spacer doesn't oscillate. 

 

i know it's a terrible spot to grind ... but when you have no choice ...
 

The ring gear spacer is thinking outside the box.  I like it.  Seems like lots of areas to work to produce both proper contact patch and carrier to case clearance.  I won't get to work on it until later this winter but I like having your ideas.  Thanks.

That project is still on the shelf.  This winter has brought several other household projects that have taken priority.  I don't see being able to start on the new differential for a few months.  You know how busy life can get sometimes I'm sure.