I've heard that both T3's and P.a.s.s. Racing's LSD rebuild kits use factory Toyota parts.
They include the thickest (1.85mm) available outer plates, or "adjusting washers
". It is these two outer plates that are "extra thick".
The two outer plates usually vary in thickness (from 1.60mm-1.85mm).
To find out their original spec. thickness, there should be a number (1 thru 6) stamped on one of the "tabs" on each plate.
This # corresponds with the factory thickness of your specific LSD (See page RA-28
Here's some pages from the FSM to help:
Thicker plates sound like they work better, but wouldn't it hinder the locking action of the LSD?
I guess it's like DC said, if the work is done properly and the clearences are correct, then you should have a properly working LSD.