I'm glad my inexperience has helped you Mr. Red
I was told that a servo save can fit but you would have to install a low profile servo to keep the steering geometry as straight as posible. On the advice of others I'm using a core aluminium servo arm on the third hole (it has four) and don't have any promlems. The thing with standard servo horns is that they are to thick and hit the body. The servo arms needed for the cat is inverted towards the servo so even if you can stuff a servosaver and standard size servo it might affect the steering. Buy a strong servo with metal gears, add on the core servo arm and you'll be fine. Here's the link:
http://www.racing-cars.com/pp/Manufa..._RC/CR110.html
It gives you something more to anodize red....Mr. Red
P.S.Don't forget to get the Mi4 ball cups to reduce slop in the steering.