brushless losi 8b

here it is:
electrics:
spektrum 2.4ghz receiver
ace DS1015 high torque servo
9xl brushless motor
mamba max esc with brushless fan and BEC
2 ftx 7.4v 5000mah lipos
RC-monster heatsink

14/ 49 gearing (i think thats the stock amount of teeth on the spur gear?)
RC-monster motor mount
RC product designs battery tray and esc mount
proline mug shots on hong nor rims

it runs great, the motor is a little hot but the esc was pretty cool by the end
it makes quite a bit of noise however, with the metal on metal contact between the spur and pinion.

with the gearing as it is i reckon it must be hitting mid 30's which is ok for the motor and esc i am using
i will eventually probably get a Mamba monster esc but what motor would be good? i really don't know whether to go with 4s or 5s though. i am looking for a cool setup with quite a bit of runtime




what do you guys reckon ???
thanks richard