RE: Kraft servo adapter for Airtonics z
Most Kraft servos will work with a new receiver, even a 2.4 one. Kraft wire is red is plus, black is negative; and usually orange is signal. If their is a fourth white wire the you have a very old 4 wire one and the wire is for a battery central tap; it would be much harder to use them and I would not recommend it. The pulse with for kraft servos was 1.4 except for their sport line. They can easily be re centered if it is to far off. You need a very tiny screw driver.
You will need to put new connectors on the wires, I do not think anyone has adapters available. The servos are old so check them out.
Changing your RD8000 would only work if your Kraft receiver is a FM one. Most were AM, FMs are marked as such.