Thanks,

I initially switched my Q-jet out for a Holley 4175 spread bore (vac secondaries).  Main reason was that the Q jet needed new primary shaft bushings in addition to the rebuild so I sent it out for work. I had rebuild the holley (took my best guess on the power valve and jets) and retro fitted an electric choke.

Bottom line is that I wish I had never bothered.  I got the Q-jet back right away and with a little fine tuning on the jets and primary rods, the part throttle response was far superior to the Holley (even though I think the holley's jet were close).  Maybe with some more tuning, the Holley would have worked out better, but the only advantage I could see was that fuel was always at the ready with those big float bowls (car would always start on the first crank of the starter).