For General Motors. 2006 C/K, G/H, H1, MD-C J-35667-8 is required due to a glow plug change. The improved glow plug threads are in a revised location in the head and a different thread size than previous engines. J-35667-8 installs in place of the glow plug, and is used with J-35667-A Cylinder Leakage Tester to diagnose the mechanical condition of the engine.
