Throttle response problem

[Hairpin]

Hi. I'm having issues with my '79. The throttle response is bad at 1k-1.2k and then picks up and responds fine above 1.2k. I pulled the carbs and went thru the jets, checked the floats, and checked the slides(carbs rebuilt with a Randakks kit about 3k miles ago). When it continued after re-install, I started some basic troubleshooting and began by pulling spark plug wires, one at a time to see if I was chasing another issue. When I pulled #1, nothing changed...not the idle and not the throttle response....so, I checked the rest and each gave me the result I'd expected (loss of cylinder.) So my problem seemed to be with #1. Checked the valves, right on spec. Checked for spark, looks fine. Swapped plugs, didn't change. Swapped wires, didn't change. Checked timing just to make sure, and it was good. Not seeing any smoke, and at higher idles, it is smooth as silk. One last thing, only running straight gas. I'm running out of options and was hoping to coax some knowledge out of the guru's here. Any help would be appreciated.

[Rambozo]

So, what did the plugs look like, especially #1?
Have you done a leakdown or compression test?
BTW, on a wasted spark ignition it's better to ground the plug to test, not open it.