4kq, thrum at speed

[Robert Mangas]

I could use a little advice.  I just redid the suspension on my 4kq, and now 
have a sort of shudder or thrum at speed.  Tires are fresh, so I don't think 
it's that.  Bearings are 75% brand new and 25% <20k, so I don't think it's 
that.  It's either a CV joint issue  or the propshaft center support 
bearing.  Any trick suggestions on figuring out exactly where from the thrum 
comes?  (heh, that's funny!)

   There's no evidence of the typical bad CV-joint clacking.

TIA,
Robert