I wish I knew enough about proper diff & suspension tuning to offer better advice, but as a solo-basher, it isn't something I worry to much about ( truck runs in straight line and doesn't feel totally mush = win ). However, this setup sheet from Steve Slayden for the nitro revo3.3 might be a good starting point if nothing else:
http://traxxas.com/sites/default/fil...usmtChamps.pdf
If not, it would be worth visiting the
idiot forum as there are actually a lot of guys & threads about setting up the erevo to handle properly- you can still search there without being signed up/in.