The QFT Slayer 600 just went in today.
I checked the timing before removing the eddie, and everything seemed in order (10 initial, 35 total) Ran the carb without the pump running and off it came.
Since it lacks a secondary metering block the QFT went on without a hitch. Holleys usually have a spacing problem with the magnum air gap manifold vacuum port. That was a nice surprise.
What a difference! The car fired right up... no bog, no backfire, feels more powerful right out of the box! I will have to spend some time dialing the idle behavior, but I'm really happy so far. Thanks all!