How warped? 0.002? 0.050? You need to shim the top two bolts, the ones that hold the throttle linkage, to match the thickness of the housing gasket. Then see how much you are off.
I'm not trying to add more work, but if this is a new set-up ( or an old one ) AND the
f/w will be bolted back on, you mite think about " sweeping " the f/w so everything
is square. Just a thought.