Well this thread seems bare, but let me try and shed some light on it.
I'm assuming you mean performing a cradle drop for the front end? It has been done 2-3 times. Once by Rock Krawler off road in thier 7-up lift, which was a disaster. It didnt fit very well, required alot of additional work to get it to work properly, terrible customer support, and did not stand behind thier product.
The cradle drop brackets were then resurrected by our beloved Jeepin' By Al in his 12" lift
http://jeepinbyal.com/prod-JBA_Big_12in_KJ-640.aspx
it has only been done once.
The only other time has been by a member KJ Hawaii and only in moderation, about 1/2". That has worked well from what it looks like.
But as far as dropping the cradle there really is no advantage unless you want to keep stock CV angles. The biggest tire that is recommended is a 32" (265-75-16) or smaller. due to the Aluminum front diff. and you can fit that with a 2"-3" lift.