77 if you just let the car set and run at idle,then pull plugs thay will be Black with carbon build up that's normol.now if the car is missing poping out the exhaust one side or both then you have a fouled plug.plug may be wet with gas or wet oil soacked,the method I mentiond earlyer is the only way I know how to do a true check on what the plugs are doing.just driving around the pits or block the plugs will still be Black if you pull them,Test hamer down full power run threw the gears shut engine off then pull plugs.dissregard this test if locking steering colum is the only shut down method for your car.