I'm running 5k front, 7k center and 3k rear and am getting great hook up on both my 4.6 Trophy Truggy and new D8T.
This is my D8T on its first shake out run. Check out my channel for video's of the 4.6 TT as well. Now with that said, I don't use the stock TT tires. I never did and have only run a set of Proline Badlands on 1/2" offset Desperado's and this set up works great for me. Probably the best off road bash tire I have ever used.
http://youtu.be/Sx-E_AUVuE0