I just skimmed back through the thread and you are at 12:1 so that plug SHOULD be too cold. I would have started with a 284/C65YC or if you don't want the extended tip you can use the 285/C65C and tune from there.

So I've switched horses mid stream. I'm going to say get a hotter plug, verify TDC and your timing light and tune from there.

As AndyF said your plugs look bad. Sometimes looking at pictures isn't the same as looking in real life.

If there is no reason you can't run an extended tip plug, I'd use the extended tip.