Thanks so much, trying to make these changes I found that shims under rear pivot are only 3mm instead of 4mm suggested by xray setup sheet. I was convinced that they were 4mm, I have a good eye for these things but this time ...
Now it's ok.
About diff oil, I don't like so much 10k because the rear tend to be unstable and the car doesn't get some improvements on power steering. So the real problem is really the roll of the chassis, now I have to work in this way.