RE: I need help with gearing
what KV is the motor?
when I ran a 4300kv in a ecx boost I found the stock gearing to be very low. I was able to run 2.2 tires and a larger pinion without overheating the motor.
Id start with stock...check the temps. if its high, then gear down. Most likely, you will be safe running the stock gearing and will be able to gear up if you want to.