Read my plugs.

The timing mark is about at the bend, to confirm back it up 2 degs and make a run, then add 2 degs at a time until it drops mph. Then you can take out 1-2 degrees. Using the ground strap for timing can be misleading if your plug heat range is off significantly. That plug shows no heat in the threads, but could be because of limited run time. I like to cut the crimp on the plug and pull the porcelain out.