I've noticed that as power increases so does the squirrliness, if that's a word, of the rear end on WOT shifts. Is there something that needs to be improved to reduce the amount of fish tailing that occurs. I have replaced the rear upper control arms and I do have a M5400-A suspension system. Haven't done a full throttle shift on my recent rebuild until today and although I felt that I had good control it was none the less a little un-nerving. Stickier tires??