The stock manifolds and crossover are very restrictive on the 3.0. If you put on headers and felt nothing, you were either way under geared or bought crappy headers.
Look a little further back in the parts for sale section, I remember seeing 3.0 headers not long ago.
x2 Headers are one of the biggest improvements you can do to a 3.0
even a with a CAI, you can feel the better throttle response.
the 3.0 is so so restricted and detuned.
3.0 headers were for sale not long ago... a few sets actually