ACDelco GM Original Equipment 41-101 Iridium Spark Plug

Replacement for AC MR43LTS in 2007 Indmar 5.7L in Mastercraft 200 / X-2 boat. Note that the gap is larger than the gap on the MR43LTS, but it IS the correct gap for this plug in this application so no need to change it.

OEM fit, finish and quality. I bought these as a last ditch effort to fix a no start issue on my mercruiser. They fixed issues that I didnt realise I had in the first place! After it started up on the new plugs, I took a sigh of relief and quickly realised how smooth the engine was compared to before it stopped working. The picture is of my old spark plugs. If yours look like this, just suck it up and get these new ones. Easy to install, fixes many problems with engine performance, including misfires, no starts, fuel economy, lack of power etc. I wish i wouldve started with these in the first place.

Recently acquired a 2008 Chevy Equinox that had 21,000 miles. When reaching 50-55mph it would become jerky for awhile until it hitting 60-65mph. I had changed rear differential, transfer case and transmission fluids but the jerky acceleration was still there. I ordered these plugs and also new AC Delco wires and it solved the problem. It was a pain to get to the back three on the 3.4l (getting the boots on the plugs was also a challenge for these three) but worth it. The Equinox drives perfectly now. These iridium plugs should last a long time.

Mechanics kept telling me to not change my plugs yet , because they were the OEM iridium type. It was really hard to change spark plugs and spark plug wires in my 2002 Lasabre, but I followed multiple You Tube presentations on it, and managed to get it done. Although the old plugs didn't look that bad, the car engine runs smooth like a sewing machine now. The performance is noticeably better, with acceleration especially. I also put in a new air filter and will put in a new fuel filter soon. I'm NO MECHANIC, but even low I.Q. people like me, with You Tube and patience, can do this stuff. My mechanic wanted $200 to do it, even though he didn't want to do it. The next time it should be a lot easier because I got it figured out better, and I also bought specialized spark plug wire pullers ($10.00), and put dielectric gel ($3.00) on the spark plug threads and ends, which is supposed to ease removal next time. Maybe I can get 250,000 miles out of the Lasabre?

These are the proper plugs for your 3800 V6. Identical to factory plugs. This are the plugs the GM engineers intended you to use. Mind you, be ready for a royal pain if you're doing the work yourself. The rear plugs on transverse mounted engines are about to easy to get to as Antarctica. The heat shields on the wires add to your fun, making it difficult to grip the boots. I recommend you obtain a quality pair of plug wire pullers (look for a tool made in the USA), a decent socket wrench, a quality plug socket (one where the rubber is secure), and an swivel adapter for the wrench. On some applications you're going to require a oxygen sensor socket because the 02 sensor blocks access to one of the cylinders. I had good luck draining the coolant reservoir and moving it out of the way. Plus the hoses leading to the heater core get in the way. No matter how well you prepare, you may also want to perform a few good deeds in advance to offset the bad words your going to say trying to replace the rear plugs. By the way, go ahead and replace the wires at the same time. This is a pain in the neck and you might as well make it worth your while. Thank goodness on modern cars these plugs don't need replaced every 25k.

Perfect for a 03 Pontiac Grand Am GT V6. Plugs came exactly right gap. Price was incredible and a rebate; $2.00 each. Change the plug wires for a complete job. Use a thin layer of Dielectric grease inside both ends of the wire boots. Makes for a great tune up. Took 45 minutes. Only change spark plugs when the engine is cool. I let mine sit overnight in our garage. Used the TEKTON 3/8 drive flex head ratchet, 3" and 6" Stanley extensions, Craftsman 5/8 spark plug socket. 6" extension worked best for the plugs in the back. ACDelco 9726UU Professional Spark Plug Wire Set. Hardest part was getting old plug wire boots off of the old plugs. If you get new wires, than it doesn't matter if you damage the old wires. Just yank them off and through them out. Change 1 wire at a time as you change the plug. Get the parts here on Amazon it's the best price. I did mine for well under $50.00. Car has more power and transmission shifts less.(UPDATE) My gas mileage in the city has since changed from 14mpg to 16mpg. The engine starts much faster and cruises up hill without shifting. I'm happy with the results.

Easy start and power added !

These are working like a charm in a 2001 8.1 liter GM Vortec engine. I replaced the wires at the same time with these, ACDelco Professional 9748KK Spark Plug Wire Set, and a few of the old wires were badly burned up when I pulled them off, so I can't tell if the problem was in the plugs or the wires, but I heard and felt an undeniable improvement in the engine. The job of replacing all of these straightforward on this engine, despite the insanely high price that a reputable shop had quoted for the parts and labor.