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Need carb tuning help - Video of wideband O2 + vacuum

I've installed my wideband O2 "gauge" and seeing some potentially bad behavior that I don't know enough to know where to start. I tried to capture it in the video below.

The car generally runs good and throttle response feels pretty good. It is much better since I changed the vacuum secondary screw to come in earlier.

Engine is mildly modified with unknown compression pop-up pistons, 4V open chamber heads, Blue Thunder intake, big bore stainless headers.
Carb is a Quick Fuel HR-780-VS. I would be amazed if it isn't exactly as it was when it came out of the box as far as jetting.
Specs here:
https://www.summitracing.com/parts/qft-hr-780-vs

Primary Jet Size:
72
Primary Power Valve (Hg):
6.5 Hg
Primary Discharge Nozzle Size (in.):
0.031 in.
Secondary Jet Size:
83


I get 15-16 inches of vacuum at idle.
Hot idle is a bit fat at 12.6 or so.

Thoughts?
Thanks in advance and Happy New Year!

Last edited by jmardy
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