Most of the problem with the 3's on gravel is too much oversteer, Which I am trying to dial out at the moment. With more understeer you can drive it more aggressive, which should make it quicker. I wonder what the works cars used before they went to an active center diff? maybe something like the KAZZ?
if you want more understeer....change it back to the evo one front end which has a much stiffer sway bay. Then remove the rear sway bar. That was a the setup that a lot of the old school guys over here used. Some even ran with no sway bars at all...to let the whole suspension work.