danc30, in order to give you a good comment on your plugs, a couple of questions are in order. How many miles on the plugs? How much initial timing? Total timing? Type of fuel, oxygenated or not? Did you add any fuel additives to the present tank of gas? Intake manifold type? Compression ratio? Carb set up? Cam? Did you idle a great deal before pulling the plugs? Type of igition system? All of these will influence the look of the plug and influence the proper reading of a plug.
I can give you a couple of comments that might be helpful until all the info is available. Generally from the photos, the plugs look ok. They show you to be running a bit fat which is probably where you want to be to avoid detonation with todays fuel. It also appears that you might be running a hair too much timing. I can't tell for sure from the pictures. There is what is commonly called a burn mark or timing mark on the ground strap. From some of your photos the burn mark appears to be way down the ground strap toward the threaded portion of the plug. This usually means too much timing. The burn mark should be toward the apex of the curve of the strap near the top to be "right on" in most applications. Also without being able to see all the way down the center ceramic coated electrode to where it bottoms out, it is hard to say exactly if your air to fuel ration is close. #4 could be that way because of the manifold runner/carb set up at idle. The flash from the camera can cause all kinds of color mis-interpretations, but #7 might have a little "coolant burn off" indicated on the ground strap and the electrode tip.
I just saw your other post. It sounds like you may think it is a head gasket issue. I am not sure that's the case but here are some tips. Have your run a pressure test on your coolant system? A head gasket leak will often times show up. You might want to run a cylinder leak down test on the #7 as well as the others when it is cold and then again when it is hot right after you bring the car back from a run. Most of the time with a blown head gasket you will get water in the
oil and
oil in the water. How does the
oil on the end of the dip stick look? Any oil in the coolant? Does the coolant smell a little like exhaust gases when you release the pressure in the morning when it's cold? One of the simplest ways is having a radiator shop perform a simple test on your coolant to determine if it has combustion by-products in it.
In the good old days we would pull all the plugs, pressurize the coolant system to its max with a coolant system pump, disconnect the coil and turn the engine over with the starter. You will be suprised at how easy it spins without compression. After a few short runs, if the head gasket was leaking, coolant would begin to dribble or spit from the cylinders affected.
Good luck. I hope some of this info helps.