Well, I ran the exotek spool and a 72 spur and I started at a 24T pinion and ended up with a 26t pinion. I just dropped the diff back on and the recommended gearing 70/25 seems right to me. I run a fantom V2R 13.5 motor. I hear about this 76T.... Is Tekno coming out with a 76T spur? Or is just people's wishes?