You really have to read the threads related to the 1-2 Bang Shift closely. Not because of their authors, but because of the content. The bang shift happens under certain conditions. Anything outside of these conditions does not quailify you as a canidate for the fix.
To make it simple; If you accelerate at somewhere around wide open throttle and release the gas pedal just before the shift to 2nd and there is a bang (or harsh shift) then fine. If not, then there is another problem and I would suspect that it would be the Solenoid Pack, Valve Body or Bands.
