8 3/4 Sure Grip Info
Shouldn't be any shim on a 8.75 for the carrier bearings. Backlash and preload are set using the spanner adjusters.
If you have a current case/pumpkin that you want to swap out an open for Sure Grip, really easy. Get a backlash reading on the current gears, you'll want to reset it to that when the sure grip is installed.
Make sure the bearings and races are the proper units for the case number. They are different between some of the cases. Probably wouldn't hurt to put fresh bearings on the sure grip.
Set up the rear using info from a factory service manual. Get the backlash reset and take a pattern. Should be roughly the same as the original.