As BryFlyGuy67 and I have discovered, its not such an easy thing to just go brushless on the #4. If you loose the stock 4&1 to go seperates, you loose the gyro, mixer and tail esc. Those all have to be put back in to run a seperate rx. You can leave the stock 4&1 and go with a brush2less converter, BL esc and BL main. Brushless tail IMHO never worked for me and is even more expensive.