Pictures or a detailed explanation would help.
As it stands, what you've told us is way too general to even start diagnosing the problem.
How do you know there is a vacuum leak? What's the hose connected to? Is the engine idle speed high? How do you know the timing is off? Does it run rough just when idling or when at speed? How do you know there is an exhaust leak? Hear it? Smell it? Where? Does the Check Engine Light come on?
Just guessing, I suspect you have two seperate things going on. The hose, I'm guessing is the MAP line at the intake. But that's just a guess from experiance. Without knowing more, it's only a guess.
