Nerf Mastodon motors.

Hi all. Ive decided to try and mod my Mastodon and i want to make this thing a force of nature. However the biggest motors ive seen people put into it are the MTB 180s and I dont see the point of putting those motors in a Mastodon when you can fit them in a smaller flywheel blaster such as the stryfe and so on.

So does anyone know where i can source some monster motors that will fit in the same points as the present motors with minimal shell modification?