differential ring and pinion swap ?s

im am changing my rear end from 4.56 to 4.11 i would like to know what will i need to get in the way of shims and crush sleeve is there a kit from some place that i can get that just supplys that or what ever needs to be changed?

Ever set up gears before. If not be prepared. You can get a kit, but you still need to ste backlash, preload, etc. You will need a torque wrench and dial gauge at the very least. Be prepared gear setup is not for the faint of heart.

There are a LOT of threads here about regearing. Do a search first.