Change, what are the measurements of your dish (height and width)? If you have a roundish dish, chances are its either a 1 meter or a 1.2. It could also be a .75, but the .75's have a smaller mount. The 1.2's often have a larger mount than the 1.0's. On the back of the dish, Channel Master usually put a stamp that has the mold type...
Unfortunately, none of these Channel Master AZ-EL mounts work well on a motor due to their weight.