Try heavier diff oil in the rear (Kyosho 100,000wt).
Take your front droop down (or up if you are reading from the droop scales). So that with your car sat down you can only lift the front end a couple of mm before the front wheels lift.
Less rear toe in.
Heavier rear anti roll bar
All the above will give you more on power steering......the last 2 may make your car more twichy...but than depends whether your fingers can follow!!
