Spark plug readers

Your plug shows to much timing or to hot of a heat range. There should be a slight change in color right around the bend. This is a rule of thumb. I would not change anything without knowing what you are doing with it. Race, you just back off the timing and start making runs. Keep adding 2 degrees until you lose mph. Then back off 1-2 degrees. The reason people just can’t tell him is his pictures only show idle mixture and timing and I have heard and actually see it on my plugs. You can tell if the plug came out of an open chamber LA cast iron head. For WHATEVER reason the LA head creates small triangle shaped marks on the top of the ground strap. Like 3-4 little marks. Very weird, but have seen them on my plugs. Actually looking at your plug there may be a change on the strap. Hard to see