5.3L. Vendor #41-993. 4.3L, 2008-2014. Platinum. 5.7L. 6.0L. 4.3L, 2003-2007. 6.0 & 6.2L. Iridium is the latest in spark plug technology and is an exact replacement for vehicles' original components. Iridium composition provides a high melting point and great strength, helps to provide excellent wear resistance and durability. Iridium offers excellent engine idle stability, reliable cold starting, quick acceleration and smooth performance. Three Piece Fired in Suppressor seal meters spark energy for long electrode life, helps prevent combustion leakage and helps block radio frequencies that can affect vehicle electronics. Iridium plugs are laser-welded which provides precision welds, reduces excess debris and wear rate, thus increasing durability. This GM Genuine part is designed, engineered and tested to rigorous standards, and are backed by General Motors