What gearing are you on with the 2650? We have a 2300kv limit, and they are making tyres Hong Nor or Sweep only (as surprise surprise thats what the LHS sells and they have the sponsored drivers etc.... bleh!)
I'm starting with Andy Liu's set up give or take, 300k F and Centre diff, only have the Yellow and Purple springs for now, seems strange to me (coming from a 1:10 TC background) to run the hardest springs all round to get grip. I have the 2.0 back end so may be a tad different for me.