If I make a LAT move to a Crew Chief MOS, how is my specific MOS chosen?

I am currently a 0621, I would like to make a LAT move to the 6172-6176 Crew Chief MOS, as a LAT mover would I pick the specific MOS for my preferred Helicopter or would I just be put into the field and they'll decide for me when I go through the school house. I'm planning on going to my BN career planner soon, just wanted to go in with as much information as possible.

Thanks in advance.