I wish I could figure out how to draw on a picture. You can start to see a faint ring right at the bottom of the porcelain where it meets that square part of the porcelain.
You are to the point you need to start making clean cut plug reads. A 1/4 mile is better than an 1/8th, but both work.
You need to cut the engine clean off at the end of a full pass. Don't lift when making the pass. Cut it clean off. Also, make sure you don't lock the steering column up and crash the car (seen that happen and it wasn't good). If nothing else, chop the throttle at the end of the run and let it idle until you get off the track and onto the return road and then shut it off.
Then you can start looking at the fuel ring. I don't remember what carb you have, but if it's a Holley, and you are tuning for WOT, do not change the main jets, change the size of the hole in the power valve channel restriction. You have the cruise tune pretty close and you do that with the main jets. WOT is with the power valve channel restriction.
