Bosch(9602) HR8LII33U Original Equipment Fine Wire Iridium Spark Plug (8 Pack)

Perfect fit for our 2007 suburban LT RWD 5.3L (not flex fuel) witj 255,000 mikes on it.

Works great in my 05 yukon xl. Plugs were pre-gapped to spec.

These are the "right stuff" for that engine. DO NOT ATTEMPT TO GAP THEM and DO use a torque wrench for install that has a PROPER ("low!") range. The installation torque is 15ft/lbs and if you have a typical "mid-range" 3/8" torque wrench it may not reliably read low enough. Strip the aluminum head and you WILL swear.I've got 'em in my '02 Suburban and just put them into an '03 Express. If the wires are old examine them CAREFULLY and, if questionable, replace them. Use HV diaelectric grease (just a bit!) around the inside edge of the rubber on the wires when putting them on and you will reduce the risk of them being damaged next time you take them off.~60,000 miles on the '02 truck with them and they're still perfectly serviceable. Be aware older vehicles (anything more than 10 years old) have MUCH more-limited PCM detection of misfires; you will usually NOT get a code or even a "saved misfire count" even when the plugs are quite a bit out-of-spec or even with a wire that is occasionally shorting to the block due to insulation breakdown yet the performance impact and, if you look at the fuel trims, the degradation IS visible. The iridium plugs are more-expensive but they are just better overall and last much longer. Buy 'em.

Many years ago I bought a 2000 GMC 2500 Sierra 4X4, used. Even now it only has about 170 K original miles on it, new tires and is in otherwise beautiful condition with everything working. Even the engine runs smoothly, however I had a pronounced roughness at idle. I have no idea when the plugs were last changed, but on taking them out, I now believe that they are the original (iridium or platinum) plugs because I've never, ever seen plugs so utterly worn out. I was going to buy the cheapest plugs I could find since the truck is so old and I don't know how long I'll be driving it. Then I decided that I didn't want to worry about it, so I bought the best plugs I could for the old gal. I am rather amazed at how utterly smooth the engine now idles and I will be checking if the (gas hog) gas mileage improves too.

Best plugs for my 2003-06 ls swaps. Can't beat the price and fast shipping!

I was lazy and didn’t verify that Amazon’s recommendation was correct. This part is intended for pre 2014 (LT) engines. This spark plug has a shorter thread.

These are good plugs. Have bought them a few times from here and have had no issues. They are about half the price on Amazon then in the parts store. Make sure you check the gap. I had to pull a couple out and regap them. Over all quick shipping and decent packaging.

Get these for your gmc 5.3 motor they are better than platinum so they will last longer and they are easy to install the fit is great and the price makes it a great value