QuickFuel 880 Surging/Missing At Wide Open Throttle

So it sounds like surging under 2 separate sets of conditions? Is that correct? Then you will potentially haveto solve for 2 separate symptoms.

With hard acceleration, it would not seem that any vacuum advance would be in the picture. Easy to put a vacuum gauge on that line and see, or plug it off an test. I'd change the jet(s) and see if that changes the hard acceleration situation.

If it is surging at cruise, then that particular issue can well be in the idle circuit, which is feeding part of your fuel in cruise conditions. That involves the idle fuel restriction and idle air bleed.