K 2500 Yukon 4WD V8-6.0L VIN U (2000)
Spark Plug: Testing and Inspection
Spark Plug Visual Diagnosis
NOTE: These spark plugs have a ceramic insulator that is 3.175 mm (1/8 in) longer than earlier model spark plugs. Use a spark plug socket that is deep
enough for these longer plugs (J 39358). Failure to do so could cause cracking of the insulator and arcing inside the plug resulting in an engine misfire.
Resistor type spark plugs with tapered seats are used. No gasket is needed on these plugs. These spark plugs are a High Efficiency (HE) spark plug that
has a fine wire electrode, nickel plated shell and a platinum pad across from the electrode.