Diff gear setup info/help please

I am going to install my gears in my Isuzu 44. I have a friend that was a mechanic helping me, but I wanted some info first. I am replacing carrier and gears. New gears and master install kit that uses shims. (bought from someone that changed their mind) The gears I removed had a crush sleeve.
Can I just replace the crush sleeve with a spacer and use shims? I'm assuming install kit come w/ shims and figure you have spacer.???
Also, on my carrier that came out, it had carrier bearing shims between the carrier bearing and the carrier. ( not between the carrier bearing and housing)
Will I have to use the same setup with my new carrier? Is it the housing that determines that, or the carrier?
Thanks for any input. (any other advice is welcome)

You can replace a crush sleeve with shims and spacer but I prefer to use a crush sleeve as it makes the setup easier.