You are right to think your HD will be called regardless. It would be better to talk to the individual and asked if they will be a reference for you and if they will give you a good reference. Be prepared to give an explanation of why you are looking if they ask. Which admin team member does your evaluation? Have the same conversation with that individual as well. You also need at least a 3rd reference who can speak to your ability as a teacher and your character. Be careful not to do anything to burn your bridge with your HD or admin. You're not guaranteed to be able to find another job. I would recommend that you think about ways you can continue in your present position and be content. Its always a possibility you won't find another job. If you haven't, I would have a conversation with your HD about how you can support them and back them up. Until you have been in that position you don't know. Happy job hunting.