Would a broken fin on the radiator fan cause the truck to vibrate?

 

You bet - big time
And by running a out of balance fan you will also destroy the water pump.
You also pose the risk of having it come further apart and destroying other things, timing chain cover, radiator, fan shroud, hood, ect ect ect...

 

 

Great advice! He would be looking at so many more possible problems when the off balance fan decided too finish falling apart...

 

Fixed Fan and Fan clutched, only took me about 20 minutes. Now a new problem, when I changed the intake manifold gaskets, I thought everything was sealed and now I have a gigantic amount of air coming in really loud.

 

Huh ... from where?
If all you have is a sound my guess all you have is the whooshing sound of the fan clutch until it warms up after a few seconds and disengages.
Take the fan belt off I bet the noise goes away while it's off.

 

It doesn't sound like it hurts anything. I mean I don't have a check engine light or anything. It sounds like a massive amount of air is entering the system, after a while it goes away and then does it every now and then.

 

sounds like a vaccum line not connected. Still havent notice anything and no check engine lights?

 

Nope, no check engine lights or anything. It's also intermittent. Not something that's constant

 

I'm with odat, are you sure it's not just the fan clutch? When you first start the truck, the fluid in the clutch is cold and thick, and the clutch will be engaged. It's really loud, especially if your old one wasn't working 100%. After a little while, the fluid warms up, and only engages when needed.

If you really had a big enough leak that you were hearing it, the engine would be either running away, or it would run like crap, ie massive vacuum leak