Yes it does take some work with sandpaper and toothpaste to free up the drivetrain, the bearings arnt a perfect fit and the gears like to be ran together. But if you are really really worried about having a freed up car I would suggest the warpspeed dif cases that are allready blueprinted.

And as far as setups go, AE does get them out, and if not Its very easy by posting on blackstocks thread here on rctech and he can get ya whatever you need. Typically the same day!

Also I would really reccomend a chassie upgrade like the BMI or Warpspeed. It will make you faster, faster.