My called 3K looks a lot like the Drebin Mechanic.
Really, though, on a called 3K, my timing, as others have stated, is pretty much the same as on any other pitch. Then my call becomes a "He yah" instead of the high pitched "strike" I use on the other two. As I am making my "he yaaaaaah" call, my right hand goes from its normal position in my crouched stance and makes a big sweeping move to straight above my head. I then stand, and accentuate this with a sideways bow pulling.