Cat SX3 grip roll and high speed instability

[Gavin Collingwood]

I've been on here before trying to sort this out and I'm still struggling, I race at bury metro which is very very high bite astro and I can't seem to fully get rid of grip roll. Mostly at high speed and sweepers. I've been running schumacher yellow mini spikes with the outside row cut on the rear and the inside and outside TWO rows cut on the front. My oils are 40 on front and 32.5 on rear I'm running a 4.5lbs spring on the front and 2.5 spring on rear and running 3 hole rounded pistons with the rears drilled to 1.6mm. The front shocks are on the middle hole on the tower and outside on the arm and inside on the rear tower and outside on the rear arm. I'm maybe thinking using 2wd fronts to take away the grip but I'm not sure if its just the front causing it to roll or rear aswell? It's very frustrating as otherwise the car feels good
Any help would be appreciated
Gav