Vacuum Leak or Increased Air Flow?

I own a 2004 F350 Long Bed. This is my first diesel, and I am little concerned about a couple issues that have come up. In the interest of brevity I'll stick to one question at a time. I recently changed my air filter out and replaced it with a new Fram. After I man handeled that rediculous setup of a system that some genious engineer should be slapped silly for I noticed what seems like a vacuum leak coming from somewhere around or under the turbo. I got the new air filter in OK and it seems to be seated correctly. I can't exactly pinpoint the leak and am concerned that I might have knocked something loose in replacing the air filter. The truck seems to run just fine, there is just a very obvious sucking sound. Anyone have any ideas? I am at a loss.