I just did a smoke test on my 3.0 and smoke is coming out of the side of the Throttle Body by the big spring so I have a bad vacuum leak.
I have not tore it down yet, I thought I would look at the forum first.
Does it have an O ring or a gasket that can be replaced, or is it time to go to the junk yard for another throttle body?

 

I think there is a sealed ball bearings on either side, writing this from memory when I took mine apart looking for tiny vacuum leaks, so can't be entirely sure.
If there are ball bearings, then one should be able to replace them _ pressing them out of the aluminum throttle body may be tricky.