[yash101]

A servo this big would be expensive if it would be allowed. However, like many people already stated above, it wouldn't be allowed in a competition. If you are trying to lift the robot, I would suggest a jack mechanism, to move the wheels up and down. It would be hard to design, but it is possible. Anyways, why would you like to switch drivetrains? I think you might be able to find a subsitute that has all the functions you need. Hopefully this was a little helpful.