Reading Spark Plugs

I pulled my plugs today to get a read on them and educate myself. It seems to give off a stronger than normal exhaust smell, not too bad, always has. New exhaust out the back, new trunk seal, etc.

All the plugs have a light coating of oil on them, and I am perplexed.

383, rebuilt about 4 years ago, everything done, driven as much as possible, aluminum heads, accel distributor, 2 Holley 390s. It runs great, and very reliable. New pcv valve,and I checked it today, no oil in the line or carb (hooked to one of the carbs, not the air cleaner).
Engine has no oil on the outside except for an extremely small amount of weeping around the valve cover bolts. Intake bolts are tight.
Oil level and pressure is normal, no smoking exhaust, no oil in the radiator, no oil on the ground.

Any thoughts?

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