Holley/Demon Carb stumble

I had the day off and wasn't on call, so i slipped out to the track and did some testing. no timing equipment up at the track. just the track surface to make some stomps on. If i just need one i will sneak out the back road. but i wanted to string a bunch of them together.

This is the the same plug i posted above. pulled it off the trailer and let it idle, nothing else until it was up to 180 degrees(were my cooling fan turns on. shut it down to Pull this old plug out for a new one
View attachment 1715367898 View attachment 1715367899
With the new plug install, i made a stomp down the track and clean killed as best i could. pulled plug out.
View attachment 1715367900 View attachment 1715367901
drove back to the pits and pulled the plug again
View attachment 1715367902 View attachment 1715367901
2nt and 3d stomp when i pulled the plug i cut the picture. didn't figure this out until i got home.
The last one is hot lapping! I did 3 runs back to back and then clean kill it at the top end to take these pictures
View attachment 1715367904 View attachment 1715367905

That's as accurate as i can get Sorry some are blurry............what do you think of the fuel/jetting.....timing....heat wrange........ i want to hear all the appinions even if they differ one from another.

View attachment 1715367903Disregard this one.

Call the NGK tech line. Those guys will get you straightened out.
How Can I Get Technical Support?
Thank you for that I called the tech line and from my indications to them they recommended one heat range hotter.
I've been showing some spark plugs looking quite the same as the ones pictured here as well. I had a stumble up high and it was cured by Richer main Jets. But I'm working on completely different carburetors with seemingly a lot of the same problems. Not severe problems by any means, just slight tuning to get it just perfect..