The Velineon will fit if you take the black plastic endcap off (it just snaps on and off). Another option would be a
Tacon 3660 3500kv: it's a bit longer and has a wider rotor than the stock motor... the KV is almost identical so the top speed will be almost the same: but it has a
lot more torque: accelleration will be very noticably better. And it's less than $35 new!