This is the setup-I have run at Taplow and my car was on rails.
http://www.team-durango.com/pdf/setu...n_16_01_11.pdf
I used:
10k Front Diff
5k Rear Diff
Plastic side rails-Got a R version
I have not changed the setup since.. and run it on Astro the same Minus camber tweaks depending on grip levels ect. Hope this is of slight help