[Trans-Am Jim]

To perform a proper plug check, the engine should be run up hard through at least 2 gears, then shut off immediately at peak RPM. Pull over to the roadside, pull the plugs and read 'em.

If I idle my 427 for a few minutes then turn it off, I get plugs thet look similar. 2x4's, by their nature, idle too rich. When I do the above proper plug check, they are right on the money - tan.