Pulled head...Combustion Issue?

I think I have an injector problem. Others' thoughts appreciated.

I blew a hg so I pulled the driver side head. Engine was bored & stroked 10,000 miles ago. When I pulled the head, the #7 piston looked different.

Here's what I see:

1.#7 piston top was a coppery color with a small amount of crud on the top. Other pistons had a dark burn coloration.
2. Lower intake runner to # 7 was also only slightly discolored, others had the black burn coloration
3. # 7 plug: ceramic insert is a dark gray and the tip is dark with only a small off-white spot. Other plugs ceramic inserts were white and the tips were a consistent off white/light gray color as expected. #7 plug was a wet on the end of the threads when pulled.

These plugs have about 5,000 miles in the engine (Autolite 3923), the #7 plug wire works fine. The injectors are 36 # that have been on the car for 45,000 miles. I got the injectors used.

One other cylinder plug (#2) shows some of the same ceramic insert coloration though the tip is just a little darker than the other plugs and it was dry when pulled.

I'm thinking the #7 injector is not spraying well and may be clogged. I am sending the injectors out for cleaning and reconditioning while I have the car apart.

Any thoughts or suggestions from others understanding these symptoms is appreciated.

Thanks for the input and thoughts. The car had been tuned and I wasn't running enough boost to increasse the timing to take advantage of the methanol injection. I am running only 6 lbs of boost and using the methanol for it's cooling effect. The methanol was put on with the rebuild. (Side note: when we first dynoed the car with the methanol the KB was actually cold after the run). The rebuild was opportunistic since the 5.0 was worn out at 132k. I had the KB on the 5.0 with AFR 165's. I put both on the 331.

The other 3 cylinders are running rich, hence the black. #7 is either running lean or was impacted by the HG. I've sent the injectors for cleaning and reconditioning. I'll put it back together and may disconnect the methanol for now. I'll put in some new plugs and keep an eye on #7. If it continues to look strange, I'll get it re-tuned.

Thanks agian for the input.