Depends on what servos and what raptor. The spektrum DS821 servos that come with the DX7 radio set are not recommended for .50 size nitros or larger. So as long as it's an electric or a .30 raptor you should be fine. As long as all the cyclic servos are the same you can use the hobbico and 4th spektrum servo anywhere (I'm assuming you're thinking throttle and rudder), put the faster servo on rudder.