No, you should NOT use a Futaba crystal in a Hitec RX.

Use a Hitec crystal in a Hitec RX.

If you have any doubts about this, contact Hitec directly, and ask them about it. If they say it's ok, then it's ok, otherwise, you shouldn't do it. (I know some guys do, and report no problems. But that doesn't mean you won't have problems).