Always be upfront. It helps you more than it hurts you. The recruiters to these colleges are humans, not machines. Telling people I stutter before any interview actually impresses or sometimes when I dont tell them at the start, I tell them half way through and it surprises them because they would have either never known or simply thought i was nervous. Use it as a tool to separate yourself from the herd. Talk about is as something you work towards and tell stories about all the challenges you overcame.