a XL or Neu 1512 is too much torque for the Rustler..I am running a stock VXL Rustler with 9L and I have problems with the torque .I have the Revo 40 tooth spur with a 16 tooth pinion and it is plenty fast. A 6 turn motor will be a fireball on 6s good luck with the setup and get some vids it should be entertaining you might want to put some lead weights on the chassis to make it more stable....