What plugs ?

garyreal · July 9, 2015

Hey guys. . First post.. I have a 2001 yukon xl ..with the 5.3. 130000miles I guess it's time for plugs and wires.. any ideas on brand and gap?? Mo

txab · July 9, 2015

AC Delco plugs .040"

MS3DALE · July 9, 2015

I would stick with the OE AC-Delco's,heres a bulletin on the gap....

#03-06-04-060B: Information on New Spark Plugs and Gapping - (Jul 30, 2008)

Subject: Information on New Spark Plugs and Gapping

Models: 2004 Buick Rainier 2002-2004 Cadillac Escalade, Escalade EXT 2003-2004 Cadillac Escalade ESV 2004 Cadillac CTS-V 1997-2004 Chevrolet Corvette 1998-2002 Chevrolet Camaro 1999-2004 Chevrolet Silverado 2000-2004 Chevrolet Suburban, Tahoe 2002-2004 Chevrolet Avalanche 2003-2004 Chevrolet Express, SSR, TrailBlazer 1999-2004 GMC Sierra 2000-2004 GMC Yukon, Yukon XL 2001-2004 GMC Yukon Denali, Yukon XL Denali 2002-2004 GMC Sierra Denali 2003-2004 GMC Envoy XL 1998-2002 Pontiac Firebird 2004-2005 Pontiac GTO 2003-2004 HUMMER H2 with 4.8L, 5.3L, 5.7L or 6.0L V-8 Engine (VINs V, P, T, Z, G, S, N, U — RPOs LR4, LM4, LM7, L59, LS1, LS6, LQ9, LQ4)

Attention: Please disregard the Set Gap Per Vehicle Specification statement on the side of an ACDelco® Iridium Spark Plug Box. The statement will be removed from the boxes in the future.

This bulletin is being revised to add the Chevrolet SSR and the 2005 Pontiac GTO. Please discard Corporate Bulletin Number 03-06-04-060A (Section 06 — Engine/Propulsion System).

A new spark plug has been released for use in the above vehicles. The new spark plug has an Iridium tip instead of the current Platinum tip. Due to the different tip design, the gap of the spark plug has also changed.
The new spark plug, P/N 12621258 with AC Delco P/N 41-110, is gapped to 1.01 mm (0.040 in) when the spark plug is made.
Notice: The spark plug gap is set during manufacturing and should not be changed or damage to the spark plug may result. Any new spark plug found to not be properly gapped should not be used.