Need Quick Fuel carb tuning assistance
Just a few thoughts after watching your video.
I couldn't see what the timing was at idle in the video.
Have you VERIFIED that your tach is correct? I have 3 different AM tachs and every single one of them reads different at idle. By 2000 RPM they are all correct. I can check this because my ignition box will do that. I can set the box at say 800 RPM and the box will send an 800 RPM signal. The tach I'm using now at 800 RPM is really about 750 so that's not bad.
The tach that I took out of the car (which was purchased new) was off 130 RPM at 800 RPM. That means if the tach was reading 800, the engine was really at 670 RPM.
Your idle sounds slow to me. Turn it up to 900ish. There is nothing wrong with that. With a stick it's even less an issue.
I don't let my stuff idle under 1000 RPM. It's easier on the lifters, the oil flow and pressure are a bit higher and if you tune the idle circuit to match, you'd be surprised how much cleaner they will idle.
If you are running a bunch of overlap, or a lot of seat timing, you may want to move the idle feed restriction to the upper hole. My cam is 281/281 seat timing and 255/255 at .050 and my idle is much better with the IFR up. Which is going against current wisdom. You need to give it what it wants so try anything you can think of.
Just some random thoughts.