Try lighter oil in the centre diff, i find 5/6/2 is the best setup ive foudn so far diff wise. 3/3/2, 5/5/2 or 5/6/2 are all good, 7/5/1 was good too but slaughtered the front tyres. Higher than 6 in the centre made the rear end unpredictable powering out of corners, the rear link camber mod helped in this area too and ive heard the new stretch rear arms with the redesigned rear hubs(yes redesigned again, 3rd time lucky i guess) help with rear traction aswell but i havnt tested them yet. Ive tried alot of setups posted at the ofna forums and nitrohouse but none of them seemed to work for me, after months of tweaking and playing around im totally happy with my setup now.

With the front end dropping down issue you have make sure you have no drag brake set i found sometimes after being hard and the brakes then back to neutral the brakes would stay on a bit, i had to play around with springs on the linkages to correct this.