shims on Pinion ( and internal carrier gears )

[Nacho-RT74]

How do you determinate the shims needed to install pinion on case ? if rear bearing is pressure, I can't simply remove it to install another shim untill get the right location.

also another question... How much in and out play must have on internal carrier gears. I have seen kits are available with just one shim, but I have about one milimeter in and out play at least on axle gears. Dunno if is worn on carrier or gears. Gears doesn't look that bad.

How much deep is the carrier hole where axle is insrted from bearing area up to internal area ?

Of course being 4 gears, depending of the rest of gears location, play is increased or not...