7xl, blech. Good luck with her!

I will reiterate, be careful with screw length. If the screws touch the windings inside the case enough to cause a short, it will make short work of your motor and likely the ESC as well.

That said, 7xl is a pretty poor choice of motor for such an application. Hot running and amp hungry. It will be hard on even a tough ESC, and the motor will overheat quite easily. Have you invested in Mike's heatsink clamp ?

J.